Expression Engine came up in passing at a lunch meeting today. There are some really great ideas in there… The data modeling sounds killer (back in 2000 I began working on a KM tool w/ similar capabilities; that was interrupted by development of a vortal). I’m interested in seeing the caching and also a few of the security features. It seems that they’ve taken a lot of good techniques out there and put it all together in a unique way. It may be worth paying $199 just to look at how the internals are assembled.