I just read that Microsoft is planning on releaseing SP2 for Office 2007, as soon as April. However, release dates always get pushed back so who knows when it will be released. Although I am not a hugh Microsoft fan, I have to admit I like Office 2007, and Outlook is my e-mail client for my XP box.
I usually wait about a month before I download and install any service packs, just in case there is an unknown bug with the installation or a performance hit.
Drahusz 