Howard and Bernadette to marry in the spring of 2012! 

So, it's really gonna happen huh? I didn't see it coming but it sounds like fun! Now if only Sheldon was the best man!!!

I'm so excited! Although honestly I hope Raj is the best man. He's Howard's best friend. If Leonard was marrying I'd expect Sheldon as the best man, but if Howard picks him that's going to seem forced to me.

That's how I'm thinking about it..
Raj has the best chances cause he's indeed his best friend, Leonard has good chances cause he's also a very close friend of Howard's plus the writers will be able to show Penny as the maid of honor and Leonard as the best man.
As for Sheldon, the only way that he'll be the best man is Howard not to be in a position to choose between the other two(because of the Raj/Penny/Leonard drama) and thus to end up on Sheldon! I dunno if it's gonna be forced, but it'll definitely be the choice that will generate the most of laughter! That being said, my money is on Raj as well!

I would love to see Sheldon marry them XD because that would just seem so out there and hillarious.

I'd say Raj or Leonard is most likely to be best man. Raj being first pick most likely. Unless this happens instead: Howard picks Raj as his best man but then Raj gets drunk at the bachleor party and confess he still has feeling for Bernadette, which then makes Howard pick Leonard instead.

Then I remember this isn't a drama XD.

^that's plausible though. And Shelly as best man would only be forced if Howard chooses him first w/no explanation why not Raj. But if he ends up that way, it'd work.