Back when I was building the "theme engine" for CAREO, everything began to look like themable stuff. I kept saying "Hey, that's not hard - we can just implement that as a theme in CAREO!"
Everything from a version of the Learning Commons website, to SciQ, to a bunch of other projects, were mocked up (and some even implemented) as themed components in CAREO.
Worked pretty well, and was an awesome test of the flexibility of the theme engine.
The main drawback was that all edits had to go through a rather cryptic process of defining content in (perfectly valid) XML, crunching the content through an app that ran some XSLT wizardry, and stored the results in a database.
That kinda killed any productive workflow. All edits had a single point of waiting, and it was hard to use regular tools to manage content (couldn't use DreamWeaver much, as it barfed on XML, or worse yet, added invalid stuff). Contribute wouldn't work with the custom workflow... Etc...
We're going through iterative cycles on a few projects, and lo and behold, SciQ is becoming largely static pages (except the stuff that deals directly with learning objects - that is still generated by CAREO) - likewise for the LC website.
The moral of the story is, when you've built a pretty fancy hammer, and everything is looking like pretty fancy nails, take a good step back and think about what's really going on. Odds are, you've got more than just nails to deal with.