Hi Supacon,
It would seem you are catching on to one reason that motivated my question in the first place. If the programming model is sufficiently flexible, this aspect of DOpus could be used for a lot of very useful features, some of which have not even been thought of yet probably.
Here's another thread from this forum that might get your thoughts flowing as well.
[File tagging/searching (Was: Now, if DOpus did THIS...))
The key idea here is, give the end-user the ability to specify arbitrary groupings of items in a lister based on whatever criteria she deems useful ... and don't require them to code it in C++ or use by-hand "drag n drop". Let the list of items come from anywhere the user can think of.
Using this approach, seemingly-complex features such as those specified in the linked thread above become a piece of cake to implement.
DOpus is already part-way there with this pretty powerful feature "file collections" ... all that remains is a clean way to get DOpus to recognize real-time dynamically-generated file collections, where the generator is your own script, a database, content scraped from a search-engine-results-page on the web, or anything else your imagination can fathom.
I've been looking for a well-designed app that can do this for a long time.