WoW doesn't seem to build a significant corpus of micro-skills or anything

High-end play will teach you a fair amount about teamwork, coordination, and group politics. If you're in charge of the group, you'll gain some decent management experience - actual employees are a LOT easier to manage than WOW players. I was a manager for a couple years, and fairly highly rated within the company, and I relied a lot on my gaming experience to get me started :)

It's probably not the best environment, but for people who are otherwise fairly socially isolated, it can be an incredible experience. I suspect running a tabletop RPG would be more optimal, but that's also significantly less convenient.

I've had other friends who do high-end raids in WOW confirm that this benefited them in performing managerial duties.