Also, you can fire off-camera flash wirelessly.
Don't get me wrong, I'm happy with my T2i, but some of the additional customability on the 7D is pretty handy.
As for switching to shutter priority to control min. shutter, Rufus, I think you misunderstood the question. Setting any camera to shutter priority will allow you to control both min. and max. shutter speeds and every shutter speed in between. I'm talking about a function that sets a min. shutter speed when shooting in other modes. My thinking, and I could be waaay off here, is that if you have the ISO on auto and are shooting in aperture priority, once the camera dials down the shutter to the min. speed in an attempt to get proper exposure (say at dusk or in a church), it will automatically start dialling up the ISO to get proper exposure. At least that's how I think this feature works. I wish I could recall what camera I saw it on.