So I downloaded and installed the Microsoft Windows AntiSpyware Beta on my main PC and –so far– I'm impressed. As Chris said, the interface itself is really great looking, but for all it's pretty GUI – it seems to work even better.
On it's first run after download, it found seven spyware threats (spyware signatures or files). Seven. Let it be said that I run Ad-Aware on this PC about twice a week, and I generally don't download anything on this PC. So, right of the box the beta can claim scoreboard on Ad-Aware. I had thought Ad-Aware was the industry standard, now I'm thinking this Microsoft app is pretty damn good.
First up, before you go rushing for the download, you need to know that the Microsoft Windows AntiSpyware Beta can "only" be installed on "legit" copies of Windows 2000, Windows XP, and Windows Server 2003.
One of the interesting tools Microsoft is using is called "real-time" protection. In other words, the beta has protections against websites adding spyware to your computer from simply visiting a website. Known spyware is automatically blocked while you browse the Internet according to your user settings.
Another great feature is SpyNet. Any user can choose to join SpyNet and report potential spyware to Microsoft so everyone is better protected – sort of a global spyware blacklist program. Signatures are then created for programs that are identified as spyware so your computer can be updated to detect the new finds.