Both of these have a bug in modern Metal backend that causes game to hang on character login.
Current work around is to set engine to Metal Legacy for now.
This applies specifically to Cataclysm beta, and the 10.2.7 PTR. If you are hanging or crashing on Wrath, Vanilla, or live retail it is for a different reason.
how exactly does one do this?
Launch game (it still launches, just hangs if you try to enter any character).
Go into system options, graphics, change engine from metal to metal legacy.
I am told the bug is fixed internally, at least, so metal (non legacy) won’t hang in future cata and 10.2.7 builds.
Helpful thanks!
With that forum name, i can almost bet i know which one you wanna test Pandamonea 
^^ My people are calling me home…
Thanks for the heads up on this - have you (or anyone else) also encountered difficulty playing cut scenes? I am unable to exit the start of Remix because every time I try to start the recap cut scene, it hangs and crashes.
I did not test cut scenes. if you can get crash report ID from that (or alternativley post entire report here from your PTR errors folder)
you bet:
BD3E3DE8-60CA-4E31-BF56-5FF927766EBB