Yup, pretty much right on schedule identifiers for iPhone 3,1 (which would be the 4th generation iPhone -- likely set to debut next summer at WWDC 2010 -- have shown up in PinchMedia analytics, which tracks device usage, this time for iBART developer Pandav. (Apple is based outside San Francisco, so a SF public transport app makes sense as a test app).
To recap, the original 2007 iPhone 2G was internally classified by Apple as 1,1, and the similar guts in the 2008 iPhone 3G (radio notwithstanding) was classified as 1,2 (a minor revision). The 2009 iPhone 3GS, with its enhanced internals, was classified as 2,1, the first major revision. If the next iPhone is showing 3,1 (and we saw this in firmware leaks back in March), it should be a similar scale hardware upgrade.
We should see some web analytics for this baby soon, and of course a slew of rumors over screen size and other hardware. Oh yeah, it's ON.