Actually this is from the 27th of May.
There are new updates for Microsoft AntiSpyware beta 1 today. To ensure you have the latest definitions, click Help > About Microsoft AntiSpyware > under "Microsoft AntiSpyware system information:
Spyware Definition Version: 5721 (27/05/2005)
You can acquire the updates by ensuring you have AutoUpdater turned on (Options > Settings) or File > Check for Updates (Manual)