Hi Fil and Bernhard:
The answer is YES! (on 1.10+) (I'm proud top say so)
I needed this same funcionality you're talking about, and we had sylvieg coding it. It's working already, after a full year of work.
See some results (in catalan, but figures are figures...
Search for "Action log", and "Contribution" on http://doc.tikiwiki.org
And the best: use this feature in conjunction with Workspaces (from AulaWiki Mod for 1.9.x sites, or installed as base - core - feature on 1.10+ sites)
Cheers, and welcome to http://edu.tikiwiki.org ! (join us there)