GB updates come from samsung, but have to be approved by T-mo to be official releases, so that process is always a guessing game. They're working on it currently, but there's no ETA.
As for CM, there's no effective way to put CM7 on our phone without a good GB kernel source, which we do not have. I'm working on porting CM6 and the CM7 kernel from other Samsung phones, but our phone is very different from many of the other phones out there, and therefore requires more work and pieces to be added.
Platypus Dev Team
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