LCD displays can look quite cool, but they still lack the 3D features of mechanical watches, and ordinary meters in cars for example.
In addition, there are different display types that have different positive attributes, such as electronic ink, which conserves power and is easy to read on for long times.
Both these drawbacks could be solved (for different applications) by layering two or more displays (both of the same type or two displays of different types), where all (except possibly the one in the back) can be set to transparent mode.
That way we could both achieve really unique-looking displays with 3D features (think a watch with background LCD, but which can also have what looks like "real hands", a frame around a movie display that protrudes in front of the movie playin, or an LCD car dashboard which can be set in modes where it seems to have real physical hands.
We could also develop a smart-phone or surf-pad which is both excellent for reading books and playing games.