Fatah and Hamas continue to battle for control. It threatens to break out into open civil war with rival government and military organizations lining up on either side.
I don't know why we assume that there must be a single Palestinian state.
Remember East Pakistan? It's Bengladesh now. Separated by India from a land corridor from West Pakistan, it might as well have been on the other side of the moon. Shared Islam didn't span that distance.
So with Hamas stronger in Gaza and Fatah stronger in the West Bank, why are we speaking of "a" future Palestinian state. All the convoluted talk of building an elevated highway to link Gaza and the West Bank or some other mechanism to link the two parts just highlights how artificial this assumption is. Prior to 1967, the West Bank was Jordanian and Gaza was Egyptian. Nobody talked then of one Palestinian state (well, they did, but then they meant destroying Israel and just taking over--without Gaza and the West Bank, of course).
So even if some final status talks result in a single Palestine on the West Bank and Gaza, the divisions we see now will likely erupt in a civil war at some point. Let's make the discussion one of an independent Gaza and an independent West Bank. If these two entities want to discuss union after independence, then let them.
With so many realists eager to redraw the maps of the Middle East, why not insist on redrawing them first in Palestine?