I propose an app to replace StartPortableApps.exe.
When loaded, this app would present a dialog allowing you to select a "profile" or add or delete profiles.
I don't know if you have given much thought to profiles in the platform yet John, so it may change some of this idea when you speak on it.
Basically what I see is, separate profile folders under \PortableApps.com\Data\ each containing it's own PortableAppsMenu.ini. This app would let you select which profile to use and copy the corresponding .ini to the folder it needs to be read from, then on exit of the menu, copy it back to the profile folder.
I'd also like to see the ability to add apps other than the Platform to this profile selector app. Click the "add" button and a dialog pops up with fields for "name" "command" "arguments". I guess that wouldn't really work for adding Platform Profiles unless you made adjustments to the menu to load the profiles by argument, rather than having the Profile selector move the .ini's around.
These are my first thoughts on the matter, so they may change.
what's the obsession with profiles lately? The beauty of portable apps is that you can put all your stuff on a USB stick and have your own personal "computer without the computer". Should you want to accommodate multiple users, just give them each their own stick. Problem solved, and that keeps everyone's data private as well--something you don't really get with multiple profiles on the same stick unless you do extra work (multiple TrueCrypt volumes, for instance).
Not profiles for other people. Profiles for specific tasks. Separate Program lists, Autorunning apps, etc.