I don't have a link, but someone was discussing this earlier.
It's confirmed from some not so legal sources that bookcases, weapon racks and shelving units can be activated and you can place the items on them without propping everything up for hours on end.
The fact this is in vanilla rather than needing to be modded in is
great news. I worked a bit on some weapon rack and bookcase mods for Oblivion, and let me tell you - they weren't pretty. Having them as part of the base game is some of the best news I've heard yet.