Sony has gone and updated the firmware on the PlayStation 3 to 2.01. Here's the change list:
• Stability during playing some PLAYSTATION 3 format software has been improved.
• Stability of System Software including Internet Browser and Information Board has been improved.
• Stability of the upscaler for PlayStation 2 format software has been improved. (Playability of PlayStation 2 depends on model)
• [Remote Start] feature is changed to avoid unintended power on.
It is assumed that the "Stability" improvement fixes issues gamers were having with firmware 2.0 and Assassin's Creed.
Update your systems now!
PlayStation.Blog: Firmware Update (v2.01)