You could do that, partially, for some nodelets. As I write this, there are 57 nodelets defined, but not all of them are "in use", and some of them can only be accessed by particular groups, such as editors or gods. Some nodelets are also "context sensitive", in that their content changes based on the main node being displayed (like Approval Nodelet).

It would be difficult to change them so they displayed as body nodes rather than nodelets, though. An All nodelets page would still have them down the side.

Other than that, I think it's doable. (This after thinking about it for all of a couple minutes. ;-) If enough people think it'd be useful, it's a matter of talking someone in pmdev to cook up the page, and talking one of the gods into installing it.