I was having some issues with F11 and mplayer, in that the first few seconds of a file would be played at an odd rate or delayed at the start
load-module module-hal-detect tsched=0
Got rid of that lag, also I found that commenting out 'load-module module-suspend-on-idle' in that file didn't seem to hurt.
I also found that if you have the snd_hda_intel device and you are hearing loud pops, you might want to try this
echo "options snd_hda_intel power_save=0" > /etc/modprobe.d/snd_hda_intel.conf
After doing all that, reboot and enjoy sound again... Now this all applies to the beta, so in the future these tips may be all wrong.
UPDATE: It appears that this issue has been fixed in rawhide and so the tsched=0 is no longer needed.