Next-gen iPhone evidence lurking in latest firmware?

Could Apple possibly be working on another iPhone? Well, yes, of course -- but Mac Rumors may have stumbled upon the first solid evidence that there's a major hardware revision in the works (and no, we're not necessarily talking about the nano). Seems that the latest firmware revisions have some juicy metadata buried deep within that refers to a product code of "iPhone2,1" -- a decidedly higher number than the "iPhone1,2" representing the current iPhone 3G. What's more, an ad network is reporting web hits from an iPhone2,1, so it looks like this is very much the real deal; only question is, just what the heck is it?