Well, I discussed Windows Vista SP1 previously, and now Microsoft has turned on the deployment through automatic updates. This means that if you have automatic updates turned on to download and install automatically, you should be getting SP1 installed pretty soon.
Naturally, the process will be progressive because of the many bugs that were found during the first phases. The most annoying bug is the endless booting loop where your computer simply reboots constantly after SP1 is applied. It’s a bit difficult to get any work done when that happens. Other problems are mostly with security programs which end up broken after the patch is installed.
You can still just go ahead and download the full installation file directly from Microsoft (mostly for administrators) to get SP1 right away if you don’t trust the automatic updates.