I'm on PS3 and I've been experiencing similar problems since the 2.3 update, as well. It usually occurs when I'm changing areas or opening menus, such as the Market board. The screen freezes and my PS3 locks up, forcing a hard reset (which, as we all know, can be risky). I'm hoping this doesn't brick my PS3 after having to do it four times since the 2.3 update.

I also noticed a sharp increase in lag and a shortened draw distance for seeing NPCs/mobs.

Hope whatever is causing this gets ironed out, and soon.