Android 4.3 is on the minds of a lot of users of pre-Note3 Galaxy devices. A schedule has now leaked and been twice-verified that shows the update schedule for Android 4.3 on the Galaxy S4, Galaxy S4 Active, Galaxy S3, and Galaxy Note 2 on all 4 major US carriers, and is as follows:
This is a very aggressive schedule for a rollout of any size, especially over the span of the Big Four. Of course, these dates are subject to change, but it stands to argue that this is pretty solid.
The updates will also include support for the Galaxy Gear.