Recent patch apparently messed up a few things with the most obvious being graphical problems. Rockstar tried to give out a quick fix for now but supposedly didn't work according to reports.
In terms of GTA Online, the biggest problem appears to be game settings being reset.
http://www.destructoid.com/grand-the...e-289558.phtml
http://www.destructoid.com/the-gta-v...k-289574.phtml