Certainly, some of these fall into a legal gray area (Angry Bird is technically another game, even though it's obviously hopping on the back of the more popular title), but some of them are straight up scams, and the angry reviews and terrible ratings prove that's the case. Arment calls out a few companies (whose titles are still on the App Store, as of this writing). He says that developers who feel an app is infringing on their trademarks can send a message to firstname.lastname@example.org to let Apple know about the problem.
We'd love to see Apple clean house on these, but of course, we're not yet sure of their position. They may have some guidelines that define how close an app can get before it's actually infringing, but some of these are clearly over the line. We'll have to wait and see what actions Apple decides to take.