powered hubs seem to be hit or miss(or maybe i am thinking of the powered extension cables?). i haven't seen too many bad things about the carnetix powered hub in the mp3car store, but haven't really looked at it too much.
otherwise, if you have a lot of low power devices, a non powered hub will work just as good.
i ran a cheap non powered, 4 port hub with my older 945 board--had gps dongle, usb aux port, wifi dongle, and bluetooth on it, and almost everything worked just as good as if it had been plugged directly into the motherboard. i only had issues with the usb aux port, but that was not the hubs fault-- i still have trouble getting those ports to work when plugged directly into the motherboard...
so i guess a better question is what do you need the hub for?
for the audio stuff, post your questions when you get a chance or pm me.