Week 28. 32 GB, black.
Got it today (iPhone 4 launched here today (The Netherlands)). Everything seems to work fine, although 3G drops when I'm in the living room (in the living room there's a bad reception anyway (1, sometimes 2 bars) so if I grip the antenna 3G will drop.
As far as I've noticed no yellow spots. No proximity sensor issues. Battery seems fine so far, but I've only used it for like 6 hours today (in those 6 hours I used it almost all the time. I started with 80%).