Yes. I wrote it. iPhone will be a great launch for Apple and be a problem for AT&T. Why - you can read my reasons in this post which all have to with AT&T's bad customer service, shaky network and the way they treat their customers. Plus, good old AT&T just loves to nickel and dime customers which surprise is new news to a bunch of iPhone hungry AT&T newbies.
You can see this engadget poll of the number of people that have had trouble with AT&T activating their phone (no surprise for people that have dealt with AT&T for a while). The poll is running at 38% of the people have problems. Finally, you can read more about problems if you hit this link from B.L. Ochman who has a nice summary.
I wrote it before and I'll write it again. iPhone will be a big deal for Apple and a big problem for AT&T.