Galaxy S is an entire line of phones, all intentionally made incredibly similar to each other. Right now the Galaxy S line is quite possibly the best planned and executed line of phones to allow for relatively easy and fast updates because there is so little variation to account for when porting OS software between them... yet they don't get the 2.2 update.
Again, Samsung arguably has the largest and most well developed line of phones to make updating the most efficient and effective way possible.
However, they don't update their phones. What appeared to be a turnaround for Samsung, what appeared to be a promise to their customers that they were going to stay on top of updates, was BS. More and more it seems that the Galaxy S line was made for the purpose of lowering the costs of production of the handsets, NOT for the purpose of maintaining the handsets that were already sold.
IMO, 'Samsung' must be a Korean translation for caveat emptor... or at least, that's what it is becoming.
/rant