Please forgive me, I haven't been on PA.com for a while and I think I missed this discussion, and now I can't find it. So, I am going to ask.
A while back there was some discussion of an improvement coming out for PA. This was going to help with checking for updates to applications, and installing them automatically every time someone starts PA, which would be especially helpful with programs like Clamwin. I am not sure if anything ever came out of this or not. Just figured I would check.
Thanks for the info!
It's coming out officially with the PortableApps.com Platform 2.0
Also, due to the way ClamWin stores its virus definitions, this wouldn't actually do much good for ClamWin. ClamWin itself only updates if the program itself needs updated (bugfixes, etc); to update the definitions, open ClamWin and click the update definitions button (on the top, second button on the left, right below the Tools menu, looks like Earth on a page). This allows the ClamWin team to update their databases without releasing a new version pretty much every day.