well, don't forget a political-economy analysis but before we go there, also don't forget the Alex Comfort's "natural" look was as contrived as anything else. http://blog.pulpculture.org/2006/02/04/shaggy-vision/ (a NYT piece on comfort, from a culturally right reviewer. Doug posted it here way back when).
Still, the rise in a lot of this stuff has to do with the rise in women's disposable income. You wouldn't see waxing come off as a viable daily regimen in 1959, I don't think. That doesn't mean that is the only reason for it. It's also a form of distinction in Bourdieu's sense: a way to distinquish oneself from the unwashed masses, etc. etc.
In LimpDick, shaving is very popular for het men. Tell me about it: coz who gets to shave the kid's body? Who gets to wipe off the nair. Moi. For young men, to go to the beach with a hairy chest, is to be like someone who wore a pair of Wranglers to a Ramones concert in 1982. There is, of course, the Remington Manscaper which I blogged about a while ago for it's hilarious comercial featuring various fruits and vegetables.
And yeah, men will be wearing perfume as a matter of course in 5 years, no doubt. Body spray is already the rage.
Que: cultural politics war over the importance of good grooming as signal of your loving, unselfishness toward your fellow human beings.