While GMail gets the job done quickly when it comes to push e-mail, if you use any other sort of account for dealing with your day to day business you don’t get the same expedient delivery times. SEVEN offers a solution to this problem, and while not as quick at retrieving messages as GMail, it shaves a good deal of time off of the standard e-mail app.
SEVEN actually consists of two separate services, SEVEN IM and SEVEN Mail. The IM service currently supports Google Talk and Windows Live Messenger, but AIM and Yahoo should be coming shortly. You can get in on a beta right now by downloading it here if you are looking for a solution like this, as SEVEN seems to offer a pretty good alternative.