This isn't a low- or medium-priority fix -- this is something that Samsung, T-Mobile, and AT&T should've been working to get out immediately. Actually, let's step back a bit: this is a problem for which there's no reasonable explanation why it made it all the way to retail devices, and it raises concerns over just how well these products were tested (you might remember from our review just how many egregious examples of weird English we found, for instance). Put simply, all three of these companies should have these phones pulled from shelves until the problem's fixed, should be communicating tirelessly with customers and the press to make sure that everyone knows the status of the issue, and should have a fix available right this second. Android's ecosystem has proven just how important frequent, reliable firmware updates are, and Sammy's already working from a damaged reputation thanks to the Behold II debacle. Let's make this right, guys.
Update: We've just received an official statement from Samsung on the matter:
Update 2: Several readers have pointed out that there are workarounds for the problem available -- we've got one linked in the More Coverage section below which points to an Android Central article. It's a good start, but not one that's practical for the average phone buyer, bearing in mind that most folks aren't power users (and, sadly, don't read Engadget Mobile). That still leaves the impetus on Samsung to get an official firmware update pushed out on the double."Samsung Mobile is aware that under certain conditions, the GPS on our U.S. Galaxy S devices may not be meeting performance expectations. We are diligently evaluating the situation and will provide an update as soon as possible."