Apple began seeding iOS 5.1 beta to developers Monday. The update should address a number of bugs, but deep within the code are references to two highly anticipated iOS devices: iterations of Apple’s iPad and iPhone.

The beta of iOS 5.1 includes mentions of “iPhone 5,1” and “iPad 3,3? within its source code, as well as “iPad 2,4“. iPad versions 2,1 through 2,3 are known, existing models. This suggests that the iPad 2 could possibly be coming to a new carrier — Sprint perhaps? — and be dual-mode, working on EVDO and HSPA 3G networks. As for the “iPad 3,3? reference, it’s possible that the iPad 3 could be arriving in three flavors: Wi-Fi only, 3G, and either dual-mode or 4G-capable.

These source code mentions are good signs that we’ll be seeing the iPad 3 and iPhone 5 in 2012, but can’t be considered guarantees. Nonetheless, we have begun hearing a lot about the iPad 3 and its potential super-high-resolution display.

As for its bug fixes, iOS 5.1 should more fully address the battery life issues that have plagued various iOS 5.0 and 5.0.1 users. The iOS update should also provide developers with additional access to the dictation services of Apple’s Siri digital assistant.

Apple released iOS 5 to the masses on Oct. 12, two days before the iPhone 4S landed in stores and consumers’ mailboxes. iOS 5 brought a number of new, useful features to Apple’s mobile platform, including notification center, keyboard shortcuts and the ability to better monitor app data usage. Within a few weeks of iOS 5’s debut, however, many users reported significant battery issues that left their phone or tablet needing to be charged after only a few hours, whether or not it was heavily used.

A source at Ars Technica confirmed the addition of new iOS 5.1 APIs that let developers integrate responses from Siri. Developers are still unable to give users the ability to control their apps using Siri, but apps could utilize Siri’s dictation-based text input abilities.

Rumors had suggested that Siri would gain additional functions, such as integrating with the iPhone 4S’s camera so you can tell Siri to take a photo or video. This does not appear anywhere in the documentation for iOS 5.1 beta, however, and doesn’t seem to be part of the iOS 5.1 update.

BGR has a full list of the known issues and fixes address in iOS 5.1, if you’re interested in the nitty-gritty.

Screen Shot: Filippo Bigarella/Twitter