even as I was thinking to myself "But now you have an attic and a basement you can fill with more stuff!!"

Hee! Yes, I'm kind of having the same conflict. I'm still living in the same place, but I asked my roommate to move out some months ago, and now have the run of the house, including a very large closet, room to put up at least another bookcase or two, and the whole of the attic. It's tempting to just not make any decisions and focus on organizing and boxing it up properly (with archive boxes, etc). Working against this, however, is my desire to have the house look less 'cluttered;' I have a lot of nick-nacks and whatnots on shelves and table tops that I think I would like to put away, so that my environment will look a bit 'cleaner'. I also realize that some things I have stacked up in files and boxes really are junk that I don't really need, if I think about it.

That's a good point about attic fires--I hadn't really considered it.