|Maybe the Saudis just like muddying the waters for political science majors. They were put on this Earth to make my life difficult. Seems to be as valid an explanation as anything else I've heard.
The Saudis gained a measure of credibility with Europe and the U.N. by proposing it. It gives the doves something to endorse as a way out, without those doves taking any responsibility, since it wasn't actually their idea.
It cost Israel standing in a way I can't quite puzzle out. Nonetheless, Sharon's administration now comes off as more hardline and uncompromising than before, even though their policies remain unchanged. SA has managed to throw up a smokescreen to make it seem as though they are refusing a legitimate attempt at compromise.
It is paying lip service, at least, to the missions of Cheney and Zinni in the region, at least those parts of their missions aimed at promoting regional stability.
On the other hand, the Saudis had to know that Israel could never accept it. The Golan Heights are too strategic to surrender. In addition, the odds of this plan actually stopping Israeli-Palestinian violence are nearly nil. It almost certainly leaves Arafat in charge of the Palestinians, which is increasingly seen in Israel as an unviable option. In addition, it will give Arafat and his organization time to regroup and rearm (or continue to arm) for future engagements, for which Israel will be less well protected.
Then again, it could be that it's simply my attribution biases making me say all that. Saudi Arabia may simply be sick of all the violence in their own backyard, sick of seeing their region derided as the slum of the world. It may also be that the Saudi royal family is beginning to feel heat from internal pressure getting sick of their rule, and possibly their hardline approach to Israel along with it.
Whatever the case, they seem determined to remain a wildcard throughout this whole mess. For their sakes, I hope they're as good at escaping webs as they are at weaving them.