Ars: Oculus Rift preview event suffers from VR tracking woes
This is worrying.
Oculus may very well fix this issue in the next two weeks. In the meantime, launch game developer Playful Corp, the creators of pack-in launch title Lucky's Tale, confirmed that they had seen this issue in testing and "were unable to repro" the issue. The team actually had to restart my Lucky's Tale demo twice before the tracking issue disappeared.
This is worrying.