That's a software issue, not a function of the 3g. As far as I know, Imap already works, what other issues are there? Push? I'll have to look into it -- I had someone else say something to the effect of, "Apple needs to get email working the way Blackberry does", so I do know it's an issue, I just don't know what it is.
EDIT: Just found an article that synopsizes the problem. Looks like the answer is going to be, "no".