We're hearing that the first beta of iOS 5.1 is just now making its merry way to iPad, iPhone and iPod touch developers, and it's already borne some fruit — namely, a string of code that references a brand new product, the "iPad 2,4". In case you're not familiar, Apple typically provides such product codenumbers in new releases of the software, though it's unlikely that the iPad 2,4 is a next-generation iPad 3. 9to5Mac, which found the digits, speculates that it probably refers to a soon-to-appear Sprint version of the existing machine. We'd like to think that the number-three US carrier would get a special nod from Apple, after risking so much money to make the iPhone 4S deal. Find the iOS 5.1 release notes at our source links, and let us know if you spot anything else that Apple might like to keep secret!