Puppy Face , Sep 04, 2009; 09:16 p.m.
According to the specs the 7D can function as a Speedlite transmitter, similar to the ST-E2. The popup lacks IR AF assist so I'm guessing it pulses the popup for trigger commands so it might be really irritating compared to the near IR pulses of the ST-E2.
The 7D PDF manual is available at CAnon USA if you care to actually read about specific functions. It looks like an amazing camera and Canon skipped a couple generations compared to their normal evolutionary update.