Exchange Migration: Hosted -> Internal

[StarTrek4U]

We're kicking off an Exchange migration bringing it in-house and away from our crappy provider. I've got two exchange boxes setup (one active, one for DR) running exchange 2007 SP1 and am right now in the planning phases of this project. I'm wondering if anyone has done something like this before (since I haven't) and if there are any catches that I should be looking out for, etc. Any input is appreciated.