On most HP Envy laptops the snd-usb-audio module causes the system to become unresponsive and Gnome Shell 3 to crash. This effects every kernel I've tried from 3.3.4 on up to 3.7rc8. It also produces these errors on the console:
ALSA sound/usb/mixer.c:415 cannot get current value for control 2 ch 1: err = -22
ALSA sound/usb/clock.c:228 3:1:1: cannot set freq 44100 to ep 0x1
Blacklisting this module allows the system to function, but with most of its speakers not working. It also prevents use of other USB audio devices, making multitrack recording impossible.
I have a ticket about it in the Fedora bug tracker, but was referred to alsa-devel. That ticket links to other discussions of this bug, as well. Here's that ticket: https://bugzilla.redhat.com/show_bug.cgi?id=884368
alsa-info is here: https://bugzilla.redhat.com/attachment.cgi?id=658989
Please let me know if you need further details, or if there's anything else I can do to help troubleshoot this.