0install will make a difference!
I'm very fascinated by 0install. Now that I've found it, I know what's been missing in my life ;) This project might just be the one that proves the worthiness of Linux to the masses? In any case, I am convinced this software will grow up and make a difference in the world.
However, how does one envision the use of this in larger environments? Imagine being responsible for ~100 computers in a corporarte environment, and you want to limit the strain on the line due to people on workstations caching the same software. Now, there are probably (nay, certainly) many ways to do this, but a neat way would be to have some sort of zero-install proxy-server that caches software requested by the workstations the first time and (transparently) serves it to any additional workstations, running zero install, wanting to start the same program. Programs would then be cached on the proxy, and on the workstations themselves.
Anyway, I digress. My original thought was: does it let any user run any program? In many administered environments, there are certain programs you do not want regular users to be able to run, be it games during work hours or other things that upper management or stern administrators consider counterproductive or destructive. As such, it may not be a bad idea to have some mechanism which lets someone control what programs can and what cannot be run.
Well, I don't suppose it's worth concentrating on this sort of issues at an early stage of development. Tools like that will probably pop up all over the place with time...