We've come a long way since the first IO result came out. Since then, we've gotten a couple more multilinear map candidates (though most are now broken), and some simpler constructions, but we're still really far from IO with a proof. This is primarily because of the underlying multilinear map that's being used. The Gentry et al result that proves IO secure in the generic multilinear model isn't that useful yet simply because there have been so many nongeneric attacks against mmap candidates, especially when they're used in IO. That is, at the moment there's no reason to believe that the generic multilinear model is even a good way to think about IO security.<p>What would be a really big result is finding IO that doesn't rely on multilinear maps.