I don't think 2 million lifetime is out of the question. It's a fantastic value selling to a larger userbase than Prime 3, so I think it can outperform that title. Then again, I am a bit of an optimist.
By first month, do you mean month of August or the first four weeks after launch?
"The worst part about these reviews is they are [subjective]--and their scores often depend on how drunk you got the media at a Street Fighter event." — Mona Hamilton, Capcom Senior VP of Marketing
*Image indefinitely borrowed from BrainBoxLtd without his consent.