I picked up my graphite GT last Saturday. It was the first GT the dealer received and it was the only color I wanted. The dealer was expecting another bike (blue, I think) in the past few days.
Interestingly, he told me that BMW's policy is that the more quickly the dealers "roll" the bikes, i.e., either sell them or put them out as demos, the more quickly they will receive more. I guess that implies that BMW is somehow metering the availablitly of the GTs rather than just shipping them as equitably and as soon as possible.