err, does this break the use of tasks with apt-get later on? I've found it very useful to do (for example) "apt-get install task-x-window-system" after getting a machine otherwise working (in particular, that's the easy way to go to xf4 - install 2.2, then point to testing, then apt-get install task-x-window-system which pulls in the right things from testing...)
Does it not also make it a lot harder to update and experiment with tasks? (Couldn't this also be handled by dropping non-critical task deps to "recommends" or something like that, and an apt-get option to "try to get the recommends too"?)

