Yes, they're definitely more organized. There have been far fewer suicide bombers. Unfortunately, it's extremely easy for anybody to plant a bomb and detonate it remotely. I would probably go as far to say that there's no easier way to kill people than with makeshift bombs.
Lately, it's also seemed as though they're just as happy killing iraqi civilians as they are american soldiers (such as a that restaurant bomb last week). Personally, I think much of the insurgent battle is caught up in itself... the excitement of creating chaos and foiling any plan for democracy. The bombings seldom have a purpose. The majority of the destruction targets numbers, rather than political or military icons. They do this because any death in iraq is pinned politically on the US, regardless of who did the killing.
It's just my personal belief/hope that the iraqi people will just grow so sick of the pointless destruction that they, in some form, rise against it.
It would also help if countries like Syria would put up half an effort to help control the flow of fighters into iraq. But that just boils down to bad politics.
Meanwhile, the american public is too busy drownin themselves in shitty reality shows and regurgitated sci-fi flicks to avoid more serious issues