You can do some crazy stuff with pistons! Ive seen a secret passageway all the way through a mountain. With pistons moving other pistons, theres no end to what you can do lol.Personally I'm loving the pistons in 1.7 but I'm struggling to include them in existing builds, just not enough room for all the circuits, although repeaters help a bit... Every new building from now though are gonna have whooshing piston doors
Circuits also take up way too much space. I don't see how Notch could change them drastically though.