I loved the skyway, was sorry to see it go, but I don't think it should be brought back. There is really no good reason for it. It doesn't transport a whole lot of people at a time, it can't go through the Matterhorn anymore, it keeps people from walking by shops where they drop cash, and we ought to walk anyway.
I would like to see some sort of innovative mode of transportation between the parks... DCA, DL, DTD... maybe even the new Garden Walk area. But a skyway wouldn't work for that. Neither would the current Monorail. Perhaps a people mover system... I dunno.
But no to bringing back the skyway. Its a sweet, nostalgic thought, but I prefer a towerless park.