If you have gmail, no, it will not. Microsoft Exchange with Push Email work solely with that – Microsoft Exchange. Gmail can either be used via IMAP (which is great, but not pushed) or POP3 (which is not great and not pushed). Exchange is typically used for business applications and corporations. MobileMe, on the other hand, is “Exchange for the rest of us”, and I, for one, could not be more excited about it. I plan on used MobileMe Push Email alongside my spiffy new iPhone 3G. Mmm.