Apple's Software Update is great and all, but unless you've purchased a membership to MacUpdate or VersionTracker for their software management clients, it might be tough to stay on top of new versions of all your non-Apple software. Sure, more and more developers are building in support for Sparkle, the auto-update framework from Andy Matuschak, but that's on a per-app basis and it simply isn't a development standard yet. Luckily, for the rest of us, there is AppFresh, a new utility that is perhaps best described as 'Software Update for the rest of us.' It can scan your Applications (though, for now, we suspect only apps in your main directory; not any that might be in ~/Applications if you've created it), AppleScripts, widgets and even Preference Panes to see if any updates are available. We don't know how and where AppFresh is checking for new versions, though Apple's own Downloads section and possibly MacUpdate and VersionTracker are the likely candidates.
Since AppFresh is truly brand new (only at v0.2 so far), its developers warn that it is certainly a work in progress. Still, this looks like a great tool with a lot of potential. AppFresh actually does seem to use Sparkle to help you stay on top of its own updates, and you can also read up at the development blog for more info on just where AppFresh is headed.