I spotted this recently in our IRC channel: Tiki needs a wiki plugin enabler, as I'm worried that many of the plugins are a security threat.... like the recent LSDIR{}
So basically we need to discuss and design an installer.
Do we really need one?
Yes, many things in tiki's cvs, such as themes, are basically just colour variations, there are very few, that actually visibily change the way tiki looks. 3dblue, adds drop shadows to the modules, there are now 3 different colour variations of olive, and 4 colour variations of the metal design. They could all sit on mods.tiki.org with a suitable installer to allow the packages to be installed.