No, this isn’t the long-awaited Beta 2; it’s yet another refresh of Windows AntiSpyware Beta 1:
The latest beta refresh, build 1.0.701, extends the Windows AntiSpyware beta expiration date to July 31, 2006 and provides new signature updates to help protect against recently identified spyware.
Existing users of the beta (Build 1.0.615) will receive a software update that includes the new beta refresh. The latest beta refresh is also available for download through this site.
Microsoft would like to encourage all Windows AntiSpyware (beta) users to download and install the new update (Build 1.0.701).
If you already have Windows AntiSpyware installed, it should update automatically. If you’re thinking of installing this program, this is as good a time as any. It’s lightweight, effective, and free.
Ed Bott 
Unfortunately, MS says not to install it on non-English Windows systems. Which is funny, because I’ve been running an earlier version on this Japanese Windows system all along.
Don’t download the new build over the old one, it doesn’t work. Uninstall the old build first. Bit of a pain in the backside but who cares.
Upgrading over the old version worked just fine for me.