The guys at Microsoft recently unveiled their "Direct Push" system, which according to this article will:
...will transfer messages straight from the latest version of Microsoft Exchange Server to devices running Microsoft's newest Windows Mobile software. The company says the approach doesn't require an extra server or other infrastructure used in the BlackBerry system, making it less expensive.
It's always fun to tear apart these marketing annoucements. Microsoft's Pieter Knook (what a name!), mentioned in the conference call that Microsoft has more than 100 million people using 'different versions of Exchange', while RIM only has 3 million subscribers. What he neglected to mention was that Direct Push will require a specific version of Exchange Server 2003, yet to be released, which means that even if the software is released later this year, it'll be a couple months before most large organizations put the release on the boxes and then probably another couple months while they evaluate the effectiveness of Direct Push. Oh, and then they have to get 3 million people to either upgrade their phone / PDA's to Windows Mobile 5.0 or buy new phones that support Windows Mobile 5.0. In short, they're still at least a year away from even moving out of vaporware status. And if Longhorn is any indication, I wouldn't be holding your breath.