There is a SP2 for Windows XP in the works, but it's still in alpha stage, and has no date set for beta testing. Unlike SP1, SP2 will be more like Windows 2000 service packs, which offer all the updates since SP1 into one big package. As of now, it won't contain any new features or major changes.
actually i believe sp2 will be out in just over 2 months. i saw a news article that said microsoft must implement java or whatever within 90 days a week or two ago and that microsoft would distribute sp2 at that time