Apple has just begun seeding the first iOS 5.1 beta to developers, intended to optimise iOS 5 and repair battery issues. They have has also begun seeding Xcode 4.3 beta to developers.
The iOS 5.1 release is most crucial among the two, and it will be intriguing to see what Apple has added, and how long it will remain in testing.
Paid members of Apple’s iOS developer program can head to their developer portal to download the updates (Xcode 4.3 is available to all developers, even those with non-paid accounts).