If Motorola's marketing strategy is to wait until September to put the Bionic up against the iphone 5 head-to-head, then I'm at a loss to understand why that would be a good idea.
If you release the Bionic now, or much sooner than the new iphone, and it has comparable or better specs, then word will spread about the Bionic and will generate interest to the point where people decide its not worth waiting for the iphone because there's a great phone out there that is just as good or better. The closer you put the Bionic release to the iphone release, the less people will know about the Bionic or if it's any good and the more they will be willing to wait for the iphone. After all, the iphone markets itself. People who aren't even in the market for a smartphone know what the iphone is. I don't think the same can be said about the Droid Bionic. The Bionic needs a head start to generate interest and buzz so that when the iphone is released, people will be confident that going with the Bionic will not be a risk. Just my two cents. I hope you are listening Moto.