Exchange 2003 can currently do a type of "push". When an email is recieved by the exchange server it sends a specially formatted SMS message to the users phone, when recieved WM2003 or WM5 picks the message up and initiates a "sync" through activesync and the emails are the recieved to the device.. Better then having it check for emails every 5,10, or 15 minutes....
Maybe we'll see media capabilities in the next BB? Maybe instead of WM5 he meant BBos5?