Halt...I think not.
Some early snags due to unfortunate showstopper bugs in Samsung source code...we got a point.
Captivate and Vibrant (and probably Fascinate) are really really close in terms of the hardware. Fixes that are discovered on one are likely going to be ported on the others in a matter of weeks. Besides that, the Captivate is going to be the biggest seller among those three, as T-Mobile has a significantly smaller customer base than AT&T, and Fascinate has many more high end Android alternatives on Verizon. It's early in the game, but support is bound to follow the popularity of the device.