Well, at least the G-20 summiteers made nice and pretended to appreciate one another, even if (thankfully) they weren't able to get together very effectively on new ways to oppress us with less and less accountable international institutions. At the Arab Summit in Doha, they weren't able to achieve even that. Hosni Mubarak didn't even show up, for the second summit in a row. Nothing was accomplished and it ended a day early.
Again, shed no tears. The idea of Arab summits and some kind of common Arab agenda is a bit of nostalgia that should have gone out with Nasser. These countries share a language (though dozens of dialects) a nominal religion (with several sects) and little else. There's little reason for them to have a common agenda, except perhaps to be concerned if Iran gets out of hand, which it isn't, no matter how hard the neocons try to convince us it's an existential threat. It's neighbors, who would be actually threatened if anybody were, think they know how to contain it, and they get together enough to make sure that's still the case, Otherwise, summitry is mostly gesture.