Source: http://www.nintendopower.com/images/NP250_DLmega.jpg  

• There is a third playable character, as well, but Capcom's keeping the hero's identity at press for now.

John Madden

I hope it's Roll.

Gerst Man.

I'm betting on Bass, personally.

Sheep man 

Playing as Roll would be an awesome twist.

" John Madden "

" I'm betting on Bass, personally. "

" @Lilarcor said:

" I'm betting on Bass, personally. "

At least he was a playable character in the past.  He was pretty kick ass too.  You could shoot in 8 different directions.  However, I doubt that would be the case as Bass was designed when 16-bit machines were made where they could provide more detailed sprites. "

" @Godwind said:

" @Lilarcor said:

" I'm betting on Bass, personally. "

At least he was a playable character in the past.  He was pretty kick ass too.  You could shoot in 8 different directions.  However, I doubt that would be the case as Bass was designed when 16-bit machines were made where they could provide more detailed sprites. "

Yea, I doubt it's Bass too, but he was an awesome character that I'd love to see more of.  If they haven't yet revealed the third character it might be someone completely new, or at least someone that hasn't been playable thus far.  So Roll is a possibility I guess. 
 
Edit:  I was just reading from the list of characters on Wikipedia and under Bass, it says " Bass will make an official reappearance in the game's sequel Mega Man 10 as a downloadable content character."  This could be false or just pure speculation on someone's part, but if it's true...then does that mean Bass is the third character but will only playable through DLC?  Or will the third character be someone entirely different, and in addition to that character you also get to download Bass?  "

if its not Bass, it might be Roll, or even Duo. heh, thet might even do craziness and allow you to play as X or Zero even!

I think it's Roll.