And even if they do release a Google maps app, as someone has stated, it won't help all the thousands of existing iOS apps that use the built-in maps. They will all go from using decent Google maps on iOS5 to rubbish Apple maps when running on iOS6. As a map app developer this is the most annoying part for me.
That is a bummer, I hadn't thought of that angle, besides iPhone customers I guess that's another group that will get sideswiped with this update - who'll want to buy those when their base source is so bad. Serious bummer.
Alternatives Map Apps will be getting tried out and used at this point.