Curious bloggers poking around the latest iPhone firmware update stumbled upon something pretty interesting Wednesday: An innocuous line of code that might—just might—indicate that a major new iPhone model is in the works. Let the speculation begin!

The bloggers at MacRumors popped the hood on iPhone firmware update 2.2.1 (which arrived on iTunes earlier this week) and found a line of code designating what appears to be a new iPhone model: "iPhone2,1", to be exact.

As the MacRumors post explains, Apple's firmware code uses different identifiers for specific iPhone and iPod Touch models; for example, the original iPhone was "iPhone 1,1", while the iPhone 3G is "iPhone1,2".

OK, but maybe we're just talking a new iPhone 3G with, say, 32GB of storage, right? No, says MacRumors: Historically, model numbers in the iPhone/iPod Touch firmware code only change for full-on hardware revisions, not storage updates.

Interesting … so, what does it all mean? Well, the timing makes sense; the first iPhone came out in June 2007, the iPhone 3G arrived in July 2008, so it stands to reason that a new iPhone should be ready by this summer. And that means … yup, it's time (yet again) to rev up the iPhone guessing game.

For now, of course, there's precious little to go on; as AppleInsider notes, there's been some idle chatter about multi-core graphics, pumped-up ARM processors, and faster 3G communication chips. Another lingering rumor—the iPhone Nano—was pretty much scotched by acting CEO Tim Cook during Apple's earnings call last week.

So, given that there's no real hard evidence besides the MacRumors find, we might as well just start by pulling out our favorite iPhone wish-list items (and remember, think hardware features, not software additions like cut-and-paste or Flash support that could arrive via a firmware update).

VentureBeat has a couple of good guesses, including better battery life (perhaps borrowing the technology behind the "adaptive charging" battery in the new 17-inch MacBook Pro), and (at long last) a better camera. Personally, I'd love to see a 5MP snapper with autofocus and a decent LED flash.

Let's see, what else … stereo speakers, maybe? (Nice, but not really a necessity.) A slide-out keypad? Nah. Thinner and lighter? Perhaps, although I'd rather have better battery life than a thinner iPhone.

What do you think? Also—what should we call this thing (assuming it exists)? The "iPhone 3" is confusing, since we already have the iPhone 3G, and "iPhone 4G" implies either "fourth-gen" iPhone (wrong) or 4G wireless networks (which, in AT&T's case, won't be anywhere near ready by this summer). I'm open to suggestions.

Related:
Next Generation iPhone Model Revealed in Firmware [MacRumors]