Okay, so I decided to go for it. Initially I had planned to download it via Windows Update and the script on Microsoft's website, but I were to find out that it didn't fully work for me. Pity. Anyway, I went on and downloaded the large update file, used by system administrators, waited an hour or so, and voila! I was running SP2 beta.
I've been running it for a few days now, and I'm very pleased with it. Vista's RAM use is a bit lower than it used to be, but not a lot. System responsiveness is better and generally very fast. I'm not sure how I like the updated search functionality. It doesn't seem to be as good as it used to be, but maybe that's just me. Oh, I've found one curious bug! I've just uninstalled Illustrator, and now the Start menu freezes once I try to remove the shortcut I had made for Illustrator. Rather odd, but hopefully they'll fix that.
Other than that, I'll await the final version, but I would think it's safe for the rest of you to update
I'm afraid I can't remember if I've already congratulated you on your upcoming status as daddy, but here it goes (again?): congrats!