ATP: Rafael, i agree the serve needs work. Safin if he stays up there can give Roger trouble as weve seen.
WTA: I dont think Maria will dominate so much. Serena can and will beat her almost routinely as long as she gets in tennis shape, shes in great shape but practicing and playing routinely.
Tatiana Golovin for sure will give the top women some trouble
Nicole Vaidisova very powerful game, strong hitter. Lindsay said in a post match interview that she can really hit the ball.
i wonder about Karolina, she lately has been sucking but i really hope that changes.
and Jelena Jankovic
Maria is alot younger than Serena. Even if in the short term Serena were to dominate her(and I dont agree with you at all, or that she will dominate Sharapova in the short term, or could beat her routinely regularly even if she wanted to but that is aside my point)
Sharapova eventually would reach the top when Serena retired or dropped from the top. Sharapova is most definitely the future of the WTA tour.
As for the men a future surprise of the current group would be Nadal. Any others that could upstage Federer we havent seen yet. Monfils wont, I gaurantee it! If I am wrong, feel free to remind me, but I wont be.