the screen doesn’t appear to be completely level within the casing
Having played with several of these in the Apple Store, I encountered the defect on just one. The degree of tilt is pretty small, but it is noticeable (and surprised me). Assuming Apple hasn’t replaced the model I saw Saturday at Montgomery Mall (MD), you can see for yourself – in the front section, check out the silver Nano attached to the iMac furthest in on the far left.
Supposedly Apple is replacing these units. As they should.
Bonus coverage: The iPod Touch teardown seems to indicate the device doesn’t contain anything resembling Bluetooth.