Scope privileges to package types or object types? I don't know, I haven't spent the time to examine it in detail and come up with workable solutions. I see pros and cons either way. But in the absence of anything else... yes, it's useful, and no, I don't 'like' it.
Neither have I spent the time rquired to work out how to get permissions to cascade between sub-packages/-direcories. I see possibilities though, which is why I said that with some juggling of packages, nodes, contexts and whatever else, I think it should be possible (same goes for the performance of the permissions system). And that's a cast-iron maybe!
