I've heard many reports since the War on Iraq started that say "things have turned around now", which were then contradicted a few months later by reports like "this has been the worst month since 2004".

So no, Bush wasn't right. It remains to be seen if the current effect will last.

And anyhow the only reason violence is down is because of Insurgents turning on each other to ally with the US army --- it has nothing to do with "the surge" whatsoever. But chances are eventually a lot of them are gonna turn their guns on the US army in the not too distant future.