I'm really looking for something that I can direct to download updates from sites of all my portable apps, which is what Ketarin does but without the .NET framework dependancy. I'm assuming there isn't one.
PortableApps latest platform beta offers application self-update capability: http://portableapps.com/news/2010-07-17 ... 5_released
That's obviously not a solution for most of the software here on the site but can take care of some of the major titles (Firefox, Thunderbird, OpenOffice).
Edit: Sorry, old news; this has already been discussed