I had problems with overheating (and often along with it, the screen going to sleep and not waking up unless I pulled the battery), even after the Gingerbread update, but I haven't had this happen since I installed a task manager and set it to auto-kill tasks whenever the screen turns off. It's been over 3 weeks since I started doing this and haven't had to pull the battery yet...previous to this, it would happen at least once a week.
I still have problems with the phone randomly rebooting 1-2 times a week.