It's not exactly a highly valuable piece of real estate. Both Syria and Saudis had designs, count out Iraq, connections are awful land-wise to Iraq. Syria seems better place to take advanatge of local instability to intervene to "restore order".So, what happens to Jordan if it experiences a collapse and breakdown in this scenario? Does Jordan get partitioned between Syria, Saudi Arabia, and Iraq?
I would not totally count out a Israeli move to take all of the orginal mandate of Paletsine (whichteh Irgun always claimed). Unlikley but more likely than Iraq., Remeber in 1956 ben-Gurin asked the French and British for the west bank, southern lebannon in addition to the sinai.Expansion was on the agenda.
I cannot see a candidate that naturall appeals to the major world players (which would make them very likely)