If you have automatic updates on and also enabled extra updates, you should have gotten Office 2007 SP2 pushed onto your machine today (if it hasn’t yet, you can force it by going to Windows Update and clicking “Check for updates”)
If Windows Update doesn’t do it for you, you can also just download SP2 here: http://www.microsoft.com/downloads/details.aspx?FamilyId=B444BF18-79EA-46C6-8A81-9DB49B4AB6E5&displaylang=en
Here’s a list if what’s new in SP2: http://support.microsoft.com/kb/953195
Note: if you have a large Outlook message store, it might make sense to wait until the end of the day to install SP2, as the first restart of Outlook after SP2 installation will cause it to update the internal file structure. You’ll get a dialog like this one:
This can take some time if your Outlook data file is large.