What that link says is that the 2.2 update is available for the Vibrant, not sure what the SGH-T959 is but my Fascinate is an SCH-I500 and this is the update from Samsung, not Verizon. You typically want to wait for your carrier to tweak it for their network, then wait a few more days for our awesome community devs to release an image for rooted phones. Those images will be even better than what Verizon pushes out, will have less bloatware and better tweaks.
There is a lot of speculation as to when we will actually see FroYo, I am starting to agree with those who think we will skip to 2.3 (Gingerbread).