This has been around for some time now and I have subscribed to this service with good satisfaction.
It's called KB Alertz, and it will scour the latest MSKB releases for any or all of the MS product lines. You can select exactly which ones you are interested in and it will email you with a listing and a link to all of the new KB articles that you have selected. It's <img src=/S/free.gif border=0 alt=free width=30 height=15> and worth a look and a subscription. GOOD information.
You can check it out at KB Alertz