All DVD-A and SACD releases have (at least) a 2-track mixdown, if not a seperate 2-channel mix. Given that you have only two ears, and that 2 properly designed and positioned speakers give a very realistic image, two channels are really enough.
Yes, if I had all the money in the world, I would buy a surround setup- but I don't. Put your money into a good 2-channel rig...
-Noah