I've enjoyed both Don and Michael's thoughts on this. I think, Michael, that a dimensional data model is going to produce the layer of meta data that you need to build this complex tool. It is, granted, a far cry from the ACS. However, I believe the metadata could be built as a seperate module, without interfering with the ACS. Then, you could use ACS 4.0 (with the full DPS that Don was talking about implemented) to reference a new navigation module that would reference this dimensional data.
Still, if all this were built, it might take a lot of changes to the ACS 4.0 adp pages, to take all their references to navigational tools out. Then we'd add references to our new navigational tool in the uppermost master.adp file. (The uppermost master.adp file sits near the top of the ACS document model. All pages in the ACS turn to it for any data and presentation information it offers.)
I don't know if I'm writing very clearly. In a nutshell, we could combine the ACS 4.0 stuff with a new navigational module and a new dimensional meta data model to get the kind of results you're thinking about.
If you're interested, we could collaborate on such an idea. I could take on the dimensionl stuff--it would take me a while, but I'm heading down that road anyway. It might look an awful lot like Ralph Kimball's clickstream datamart when I'm through with it. (He talks about it in his latest book--The Data Webhouse Toolkit). You could then build a navigational module that allows an administrator to configure the look and feel of the tool, the interaction of the tool with the meta data, etc.
It could be fun. It wouldn't be quick. I imagine it would take 6 to 9 months to get a pilot version out if we're lucky. However, by then we'd have a stable version of openACS 4.0, so maybe it'd make sense.
