I think that he will win this one. Look at the possible team he has. Right now his team shows alot of potential. And I think he has one of the best chances he has had in awhile to win the league.
yeah he is tough and he is proud. it may turn out that he is like bulnasaur--too proud to evolve. besides corpish was strong too, but it did not evolve. so, i dont think buizel will evolve very soon.
Now that I look at what Pokemon he could have by the end of Sinnoh, he does stand a chance of winning, that is, if he finally gains at least some intelligence.