I think it's great. It's fast and funny and gets the point across. Slate is whining about it. And Metafilter's talking up a storm. I like that the manufacturer shows it thinks we have a sense of humor about the emotional dimension of buying a car and that we aren't hung up about the sexual meaning of shopping.
ADDED: By getting Slate to bitch about it, Hummer got me to watch the commercial. Practically the only way to get me to see a commercial is to get some internet controversy going. Like, remember "girthy" franks?