I also don't think Gen X should go all the way til 1981. I was born in 1981, so am technically a Gen X'er. But I have never identified with that group - all the movers and shakers in Gen X seem at least 10 yrs older than me. I would rather be grouped with "Gen Y" or the "Millenials" but both terms tend to be associated with vacuous teeny boppers. The "South Park Generation" is a much better term.
I, for one, never worried too much about under which generation to classify myself. Kids are smarmy little know-it-all punks (yes, that always went for me, too) in ANY decade.
I will, however, say that every time I hear the term "Millennium Generation", I think about that stupid Sunny Delight commercial in which a bunch of little rollerblading helmet-wearing bastards introduce themselves as "Generation 2K", riding the cutting edge of societal evolution by virtue of having gulped down God only knows how many gallons of that nasty yellowish liquid sludge.
So yeah, I think I'll stick with Generation X (b. 1978). At least we had decent music. Mostly. Okay, sometimes. Sort of.
-Dan