The idea of Dogme as that it would be a cleansing experience...and you'd take what you'd learn from the experience and move on. No director has made more than one official Dogme film so far.
Anyway, I saw this this evening and thought it was amazing. I can understand Mutincyo dozing off in the first half hour or so, because it is a bit slow at the beginning, but other than that I found if pretty electrifying. Just on a technical level, the film is stunning -- Von Trier is able to pull of this conceptual type of filmmaking like no one else. It's fairly groundbreaking. And Kidman's performance, like Weak2ndAct said, is probably her finest acting to date. It's so exciting to see her maintain her integrity as an actress after becoming such a big star (even though she isn't doing Von Trier's followups, she's still committed blindly to working with Wong Kar Wai, which is just as exciting).
The actual story was great -- it follows the usual theme of put-upon women that Von Trier favors, but then takes it in such a radically different direction, going past the melodrama of Dancer In The Dark and into a realm of very black comedy. I have to think about it some more (and probably watch it again) before I can say whether it is entirely successful as a critique of America, although it is entirely valid as such. Either way, the film is one of the most original I've seen in a long time, and it is brilliant and invigorating, despite any allegorical issues it may or may not have.