Buy or wait for Win 8

I was thinking about buying a new PC that could do a better job of handling HD video than my current Vista system. I believe most of my software (a wide variety for still, video, etc) and devices (3 printers, scanner, calibrator) would work with Win 7. However, why buy an OS being replaced? Should I wait for Win 8 (it's a feasible wait) and make a massive upgrade if required or go with Win 7, which should be supported for the productive life of the PC? Based on my limited reading about Win 8, I don't see any "features" that are really important to me and it seems radically different in function (learning curve). I also haven't read anything about improved handling of problems- software, hardware, crashes, etc.

Greg