I would only consider buying paper books if:
1. It's not available in ebook - eg, lots of old 40-60's SF. Even then, I would probably wait. I've got enough on my TBR list...

2. It's not fiction and I need it for quick reference - eg, spiritual books (bible, etc) and tech/programming guides. These books are dip-in and my experience is ebook reader's are not dip-in systems.
Any new books will probably be ebook format. Just ordered 3 more last night. Dang - it's almost
too easy. That's 5 books since Christmas day