Apple has just announced that iOS 5.1 will be available to consumers starting today. Among the new features that will be included are things such as Siri support in Japan and the ability to delete individual photos within Photo Stream.
No word on whether the new iPad 3 will be released with iOS 5.1 or something higher. iOS 5.1 will probably start showing up as an update for many users after the iPad event is over today. If you manage to catch it in iTunes, let us know!