Certainly an interesting concept...I've always wished Software Update could take a wider look at updates available for my installed apps.

But results with this app on my machine were somewhat strange:

1) Many of the apps reported as outdated were not actually outdated. I don't know what made AppFresh think I was running older versions of some apps. Maybe outdated pref files hanging around from old versions? Whatever the reason, blindly following AppFresh's advice would have meant lots of unnecessary downloading etc.

2) I was very surprised that some of my major apps (MS Office 2004, several Adobe apps including GoLive) were not listed in the iusethis.com database. I realize this is not a fault of AppFresh per se, but relying on such an incomplete database is a shortcoming from my perspective. Perhaps I'm supposed to take the initiative now to update the iusethis.com database myself? Now that would be philanthropic of me...but I'm not in the mood.

I think for now I'll just continue to do my manual update searches once in a while...and to rely on the "Check for updates" feature in all my apps whose developers were wise enough to include such a feature...

I agree with the main findings of yours. But to me the glass is half full, not half empty.
All apps (about five out of 250 apps) that it listed as needing an update when in fact they did not need one were easily identified by me.

One has to see this as an additional way of identifying apps having an update available. Most biggish apps you will hear about in the news (websites), this together with the widget mentioned earlier just catch a large number of those which don't make it into the news.

The Leopard website claims that Software Update will update printer drivers, so maybe by 10.6, Apple will open it up to all apps.