This leak shows Galaxy S is being tested with Froyo. I'm starting to think that all these big Android manufacturers need about 2 months to update the phones to the next version, once they are out in the market. I haven't seen a phone getting the update much earlier than that for now.
This means Galaxy S will be getting Froyo sometime mid to end of September, because it's only been one month and half since it first launched internationally. So far, the sales of Galaxy S have been pretty good, achieving 1 million handsets in US alone. Of course, they don't sell Galaxy S in USA specifically, because in USA they have 4 different versions of Galaxy S, going to each of the big carriers: Captivate (AT&T), Vibrant (T-mobile), Epic 4G (Sprint) and soon Fascinate (Verizon).
Samsung should hurry up and update their phone with Froyo as soon as possible, so their customers enjoy it as much as they can before Android 3.0 Gingerbread is announced in mid October, because then everyone will forget about Froyo and will start craving for some Gingerbread.