Revit 2013 Update Release 2 (a.k.a. UR2) has been posted and available for download from the following links:
Please refer to the readme for the list of items enhanced in these UR2, or please see Jeremy's post here.
(By the way, we found quite difficult to find the above locations if we try to follow from Autodesk pages. You can search by typeing "Revit 2013 UR2" in the search window instead. Probably easier that way.)