It seems like everyone who got their dev kit in the past day or so has the TF2 problem, myself included. Every other demo I've tried has worked great, but I haven't tried any titles with Perception yet.
At this point, it looks likely that there was either a new update to TF2 that bonked the Rift support or that downloading it today caused us to get a new version that doesn't have the proper Rift update but also makes Steam think it's the latest ver…