I'm sure many here have used (and are happy with) Secunia PSI 1.x to keep their 3rd party programs updated against security vulnerabilities, which seem to be rolling out in ever-increasing numbers these days. For those who have not yet tried this stable program, I can only recommend you get it here: http://secunia.com/PSISetup.exe

A few days back Secunia released its PSI 2.0 beta program, for public trials and feed-back. As it is a beta program, subject to errors and problems, I am NOT recommending anyone trial it.

However, I have been using it for 2 days on XP/sp3 (after taking precautions), and note the following major changes:
- Automatic Updates: Functionality for Auto Updates is now implemented as a core feature in the Secunia PSI.
- New User Interface
- Integration with Secunia CSI
- Improved Presentation of Scan Results

Supported Operating Systems (32 & 64 bit):
Microsoft Windows 7
Microsoft Windows Vista
Microsoft Windows XP - Service Pack 2 or later
Microsoft Windows 2000 - Service Pack 4

FWIW, my thoughts:

1) It downloaded/installed cleanly (installer= 912 KB)
2) Scans run without problems, though no faster than with PSI 1.5.
3) Automatic Updates: Haven't tried this, and don't want it. For those that want to keep their 3rd party applications updated automatically, this may prove useful. I don't allow any program (including Windows programs) to auto-update, preferring to do so manually a day or two later, after others have discovered and solved the problems that come with some updates.
4) New User Interface: It is indeeed simpler. I'm surprised there seems to be no Browser Security tab, that alerts one to security vulnerabilities in one's browsers. The scanner also does not identify any unpatched browser vulnerabilities, whereas my previous version identified all my 3 browsers (IE8, Firefox, Opera) as insecure. It seems this new version only identifies browsers lacking known patches, but not browsers with vulnerabilities for which no patch yet exists. (I could be wrong here).

Summary:

In short, I see no compelling reason to use this version of PSI at this time, except for those who wish the convenience of auto-updating their 3rd party programs, and are willing to accept the risks this entails.