The Microsoft Team has posted a FAQ for the Outlook 2007 February Cumulative Update. The extended release notes for the February CU are here. Bottom line, if you run Outlook 2007, you should install this update. Outlook performance is greatly improved and the app shuts down more elegantly.
One warning – your mail files will go through a conversion process the first time you open Outlook. This can take a considerable amount of time if you have gigs of mail available in Outlook, so make sure you upgrade when you have some free time to let Outlook complete the conversion.
You have to jump through a couple of hoops to download, but it’s worth it. Go here and click View and Request hotfix downloads: