The big problem I see is that Apple effectively removed street view from the iPhone as it's not even available in the mobile safari version of Google Maps.
I don't mind that they are working on their own maps, but I can't believe they couldn't have licensed Google maps for at least another year until their solution matured or offered some sort of advantage. The first iPhone brought the best mobile maps experience. The latest iPhone brings the worst.
To me, the real test is whether Apple will allow a map application from Google to coexist on the iPhone. I'm hoping they do. It's the right thing to do.