The other thing I can't wait for is for carbon nanotube construction to hit the big time. This time I'm thinking about a submarine that's strong enough to take several people to several hundred feet of depth, and light enough to be carried by a blimp.
When it's as simple to build with nanotubes as it is to build with, say, fiberglass, all sorts of impossible things will become less impossible. (like the space elevator)
In fact economical nanotube construction methods would make the whole Zeppelin concept MUCH more approachable. Get on it, Science!