The reports are based off of complaints by a 3GS user, "Samsas Traum", who has shared pictures of the problematic screen on his iPhone 3GS. You can see the original complaints translated from German here and here.
According to iLounge: "Traum claims that the localized nature of the damage is likely due to repeat playings of Flick Fishing. While we have yet to see a second report of such extreme wear in such a short time, iLounge editors have found previous products with oleophobic coating--such as sunglasses--to be problematic, with the coating coming off with as little as contact with certain types of water."
While we haven't experienced the use of such products, like those sunglasses, we do know that Apple has specific advice on cleaning your iPhone 3GS (emphasis added):
"Keeping the Outside of iPhone Clean To clean iPhone, unplug all cables and turn off iPhone (press and hold the Sleep/Wake button, and then slide the onscreen slider). Then use a soft, slightly damp, lint-free cloth. Avoid getting moisture in openings. Don't use window cleaners, household cleaners, aerosol sprays, solvents, alcohol, ammonia, or abrasives to clean iPhone. If your iPhone has an oleophobic coating on the screen, simply wipe iPhone's screen with a soft, lint-free cloth to remove oil left by your hands and face. Please note that the ability of this coating to repel oil will diminish over time with normal usage, and that rubbing the screen with an abrasive material will further diminish its effect and may scratch your screen."
That last sentence seems to indicate that the coating does not last forever. But assuming that "Samsas" bought his phone on launch day, two weeks seems like an awfully short lifespan for the coating. We have not experienced problems with this issue on our iPhone 3GS, but that may be due to our immediate use of a screen protector after opening the phone.
If the problem persists and other users report a premature aging of the coating, should Apple offer reapplication of the oleophobic coating or replace the screens? Are you or someone you know experiencing this problem? Let us know in the comments.