The final race of the 2010 MotoGP World Championship marks the end of the road for a number of riders with their current teams. The 2011 season will begin with top riders on different brands, others staying on the same brand but switching teams, and still others moving to other championships.The most high profile move is at Yamaha, where Valentino Rossi leaves after a seven-year career that included four MotoGP World Championships. Despite breaking his leg in Mugello, and missing four races, Rossi has a longshot of taking second in the championship to teammate Jorge Lorenzo. Rossi will begin his life at Ducati on Tuesday, when the final test of the 2010 season begins at Valencia."So here we are, my last race with Yamaha and it will be an emotional weekend for all," Rossi said. "Of course I would really like to try to win this final race because it would be a great end to this partnership, which has had so many beautiful moments. We improved the setting of our bike again in Estoril so I hope we will be in good shape in Valencia, although it hasn't been the best track for me in the last few years. Anyway, this is a special weekend so we will do everything that we can. I am third in the championship after Estoril and second is not impossible, although we know Dani is strong in Valencia and he is still 19 points ahead."The rider Rossi replaces is Casey Stoner, who will be riding a Honda for the first time since 2006. Stoner left the LCR Honda team in 2006 for Ducati, where he immediately won the 2007 MotoGP World Championship. Since joining Ducati he's won more MotoGP races than anyone, 23 to Rossi's 21. But he hasn't been able to translate them into a second title. He was second in 2008 and fourth in 2009 and 2010, though 12 points down on Rossi heading into Valencia."After the awful weather we had to put up with in Portugal I hope that Valencia is a bit better and we get chance to work well and get a good set-up for my final race on the Ducati," Stoner said. "I have always liked the circuit and I had my first ever win here in 125cc. It is a tight but flowing circuit and even though there are a lot of second and third gear corners they are banked and you can let the bike run, keeping some good speed up. This also helps you to find a gearbox setting quite quickly because apart from the straight, obviously, you only really need two gears. In the past we have always been able to find a good set-up so I we are confident. I really want to have a good race this weekend."Ben Spies takes over the second seat on the official Yamaha factory team, which will no longer be sponsored by Italian car maker Fiat. AirAsia is the rumored sponsor, though nothing officially has been announced. The 2009 World Superbike Champion has already clinched Rookie of the Year honors, as well as taking a pole position and two podiums, Silverstone and Indianapolis.Spies re-injured the left ankle he originally hurt in Le Mans, and re-aggravated in Silverstone, during a sighting lap crash for last weekend's Portuguese GP. It's likely he'll finish the season in Valencia.Frenchman Randy de Puniet moves to the Pramac Racing Ducati team after a three-year career at LCR Honda. De Puniet, who missed two races after breaking his leg in Germany, is among four riders fighting for eighth in the championship; he's currently five points down on current eighth Marco Simoncelli (San Carlo Gresini Honda) and ten up on Simoncelli's teammate Marco Melandri. His best season-ending finish is 11th, which is where he finished in 2007 with Kawasaki and last year with LCR Honda."After the bad weather in Australia and Portugal I really hope to get a dry GP in Valencia which is a very physically demanding track," de Puniet, who equaled a season best sixth in Portugal, said. "I like the atmosphere there as it is another warm Spanish GP. Following on my last performance in Estoril I aim to close this season with a very good result. (Marco) Simoncelli's last performances are very impressing but I strongly want to close the gap, scoring important points for the standing. After my bad injury in Germany in July I still struggled with my leg, but I was delighted with my sixth place in Estoril. I experienced the podium in Valencia in the 250cc class and I am determined to be fighting at the front again."Also leaving Honda after a very unhappy season is San Carlo Honda Gresini rider Marco Melandri. Melandri has become increasingly vocal in his displeasure with the Honda RC212V, which he'll swap for a Yamaha World Superbike YZF-R1. Melandri needs to finish ahead of Colin Edwards to secure tenth in the championship."Last Sunday was another disappointing day in a disappointing season," he said. "I cannot explain why we haven't been able to find the key to our problems. We tried in vain and this gives me much bitterness. Valencia will be our last opportunity to redeem a season I'll want to forget. I like the track - I have won here in 250 and MotoGP - but the hopes of another success this weekend are very small and I deeply regret that."Aleix Espargaro ends his first full season in MotoGP on Sunday. The Spaniard had a four-race apprenticeship in 2009 before moving to the Pramac Racing Ducati team in 2010. But his results haven't been strong enough to keep him in the class and he moves to Sito Pons' Moto2 team in 2011. The Spaniard is only 21-years-old and a return to the MotoGP class is certainly not out of the question."The fall on the first lap of last Sunday's race was not what I was aiming for," he said. "I was aiming to achieve a good result on Estoril's track and the results of Friday and Saturday free practice sessions had given me high hopes for the race. Sunday we'll return to Spain for the fourth time this year. In the other three Grands Prix on the Iberian land of this year, I have conquered a fifteenth position in Jerez, a good tenth position in Aragon and a withdraw on Barcelona's track, a race in which I had done a very good weekend. I hope to greatly improve the position (from) Aragon," where he finished tenth, "and conclude in the best way my first MotoGP season. This track has a different flavor for me, I made my debut here in the 2004 while I was riding a 125cc. "Italian Loris Capirossi takes his considerable experience to the Pramac Racing Ducati team. Capirossi took a chance on the Rizla Suzuki team two years ago and the experiment has been a failure. This season he's scored points in only nine of 17 races, with a best of seventh in Catalunya. He'll end the year with the worst championship position since he began his globetrotting career on a 125 in 1990. Currently he's 16th."I hope we can go well at Valencia because it has been a very hard season for us and we need to end the year in a more positive way," he said. "The circuit is quite good for our bike and it seems to suit the dynamics of the GSV-R well. I know it will be difficult and I'm still not 100% fit, but I firmly believe I can go well in Valencia. It is the last race and after all that has happened this year it would be good to give my crew something to smile about - I will certainly be giving everything I've got to make that happen."Interwetten Honda MotoGP's Hiroshi Aoyama hasn't announced his intentions for 2011, but all signs have him replacing Melandri at the Gresini Honda team. The last 250cc World Champion's rookie MotoGP season was interrupted when he broke his back practicing for the British Grand Prix at Silverstone. Aoyama missed six races and currently sits 15th in the championship."Sometimes I feel quite good in Valencia, sometimes I don't, so I hope that this time I will be comfortable with the bike and the tires and that I will have the confidence to push," Aoyama said. "I quite like the track and last year I won the 250 world title there."