There are not currently any official update notes for this software update today, the only available notes are in the previous release. I did add notes at the bottom of my post regarding the sketchy update information. Hopefully someone can come out with a list of what was updated.
Here are some basic notes regarding the new update today, though there is nothing official:
Update: . AT&T tells us this bigger update contains the new Media Link code -- and presumably something else, but we don't yet know what.