The Blackberry Tilt will work as a wireless push device ONLY if your IT Department has Active synch enabled on your account.

I work at a University, I am the Exchange admin there, and I can tell you, although the default setting for Active Synch on the Exchange server is ENABLED, it can easily be disabled (It can also be re-enabled on a per user basis). I know, because we made a point to disable this feature to "encourage" users to go with BlackBerry.

Without active synch, you would need to find alternative means. Since the Tilt has BlackBerry Connect on it, you can connect it to BIS to download your corporate mail, especially if you are doing that now with your BlackBerry.

You could also forward mail to an account which your Tilt can access if you don't want to pay for BIS data, or even do wired synchs. No matter, the tilt will likely work one way or another.

I have a Tilt, and I am enjoying it, however, the BlackBerry is still a superior Email device.