Flying off to Reno, as Mad Men Season 3 concludes

The 3rd season of "Mad Men" ends on two entirely different "notes." One the one hand: as an ad conglomerate is about to buy out Sterling-Cooper the corps team (most of the main characters in the firm, but not all) put together a surreptitious plan to leave and start their own firm, at first operating out of a hotel suite. It's kind of unlikely, and kind of fun - they're like kids in one of the old movies - Let's put on a show! - and also a bit like the 7 Samurai, selecting one by one the perfect members of the team. On the darker note, not only does Ice Queen Betsy tell Don she wants a divorce and forces him to leave the house (and kids), she appears to be going through with it, heading off to Nevada at the end, baby in her lap, with her new beau (Henry Francis, the governor's aide) alongside her. I suppose it's possible they will marry in season 4, but can this last? Can either one of them be serious? Obviously he's attracted to her - he's not the only guy who is, if you like that type - but they've said hardly a word to each other, just gone through a telephone flirtation and a few brief meetings, in mostly public venues. I guess people have gotten married impulsively and foolishly before, on a wing and a prayer, but this seems pretty ridiculous and out of character, especially for Betsy. Anyway, final episode of the season mostly a plot wrap-up, though it effectively sets up some good situations to develop in Season 4. At least the likable Sal will probably get his job back!