Probably should have mentioned this yesterday, but Multiwinia is now available from the Introversion store, and there's a splendid collector's edition available alongside the boring old standard box. You can also pick it up on Steam. We've really enjoyed our pre-launch sessions with the game, and we'll probably cobble together some kind of in-depth overview next week. Y'know, if we have time. I suppose those of you already spoiling for a Multiwinia War should post your inclinations in the comment thread.
If you haven't made your mind up yet then you should probably take a look at the Multiwinia demo, which contains a bunch of maps and game modes from the full game.