'Two-thousand ten' for me. Saying 'twenty-ten' does sound slightly odd (to me, anyway). I think someone on CNN or something mentioned how we didn't say 'one-thousand nine-hundred ninety-eight' for 1998, and so on. But that would seem like a mouthful back then, so saying 'nineteen ninety-eight' worked. 'Two thousand ten' for 2010 doesn't seem like it takes that long to say, so that's what I'm going with.
In any case, Happy New Year 2010 everyone! :D