I'm attending the Exchange pre-conference today. We got here early to register and get our goodie bag. Much better than last year's "man purse", this year Microsft is giving out backpacks similar to the one from TechEd 2004 (San Diego). The only gripe I have is that the zippers get jammed all the time.
The pre-con is pretty good so far. The speakers are knowledgeable and there's lots of good hands on labs.