So, that was nice and smooth: a couple of urpmi --auto-select and this webserver and my mailserver are running 2007.1 (Spring). Will probably be more difficult to do that on a full desktop system, but it worked very nicely on the stripped down install I use for servers. Very hopeful for Spring in general. The final release looks really, really solid, we have the press arrangements sorted, the mirrors are already up and ready (as opposed to last time), I'm just a bit worried that we need to get early seeding started soon, but in general, this should go really well.