I wouldn't agree that it's a big "unless". The 3GS has set precedent for an "S" version meaning nothing more than suped-up internals.

I find it highly unlikely, however, that they would use the exact same image: they would change /something/ about it, whether it just be what the wallpaper is, to the angles of the shots. Given that this is actually the same filename being shared from the other product, it seems much more likely that they haven't put the final images in place yet.

At least for the computer icon in Mac OS, they haven't historically changed without visible design differences. I doubt they would handle iPhones differently.

I dunno - do the 3G and 3GS use identical-looking images? If so, is it actually the same file?

Note that the iPhone is running iOS5

Agreed. I see why they did the 3GS so that the iPhone 4 was the fourth generation. However, they can't do that here because then the iPhone 5 would in fact be the sixth generation iPhone, and I think Apple would realize the customer support headache introduced with that.

The 2G was actually the first generation, and referred to the mobile internet it used.

I don't think Apple worries too much about what the numbers mean, and are just keeping it paired up with the OS version number