I think that his only real competition is Geoffrey Rush, and, having seen "The King's Speech" and enjoyed it immensely, I still reckon that Bale is going to take the title.
His performance in The Fighter was powerful and emotional - even my sister, a stuanch bale-hater, who I dragged along to see The Fighter, thought he was brilliant in it.
Not to mention the fact that the IMDB polls and every other poll I've seen are tipping Bale for the win.
And, even if, by some freak of nature, he (though God forbid) doesn't get the Oscar, we will all know in our hearts that he deserves it, and always has :)

I believe Christian will win and I just know He will.
Geoffrey was good, but CB was much better and deserved this from a long time.