Had same issues, but only the first time I logged into the new patch.
Second time, everything was just peachy, and actually was around 5 FPS faster than last week. I don't know why, but it fixed itself, never touched a single setting on my rig.
*EDIT* Had to do the exact same thing today. Log in first time...mouse freeze every two seconds, FR of 2 in arena, with massive freezes. Log out. Relog.... no issues.
The one thing I did see different was the "Vidmem" and "Vid used" tags at the top of screen were different between the two. The first login had "Vidmem 0" "Used 33.4" The second login had "Vidmem 512.0" "Used 33.4"
Hope this helps find the issue.