Blizzard updated the launcher again today without warning and hopefully without incident -- unlike Monday, when everything went awry, errors abounded and people were unable to connect.
There is no indication that patch 3.3 is anywhere near downloading or anything other than a small tools patch. There has also been no word from Blizzard yet on exactly what this patch does, but it is required if you want to log into the game. The patch is very small and only takes a handful of seconds to download and apply.
We'll keep an eye on this issue for any problems, but as of this writing, all is well.