I would like to be able to hook up a mic and have Amarok output white noise out the speakers while processing the incoming signal from the mic and compare the two signals to know where any peaks or dips are for my particular room and each speakers.  And then either automatically setup an equalization per channel or allow me to EQ using an external EQ.  It should do it for each channel (please include enough for those of us using HT). This feature is basically being integrated into MS Vista.  There's a pretty lengthy discussion over at AVS forums about it right now:
http://www.avsforum.com/avs-vb/showthread.php?t=713073

I can see a problem with not everyone having a standard mic.  Perhaps, using a common PA mic like the SURE SM-58 would be the best route to go. 

I know those with standard soundcards and gear may not care so much, but I've got a M-Audio Delta 1010 in a home theater environment.  This added feature would allow me to get rid of Windows on that box and go exclusively with Linux.

I agree! That would be an awesaome feature!!!