I have just sorted through the App Store and settled on trying out your app. I open it up and you immediately ask if you can send me Push Notifications? I have no context about what these are going to be used for or why they might be useful to me.
I recently got similar advice about my iPhone game. I'd never really thought twice about asking immediately, but it really is an annoying experience. I'm looking for a better time to ask for this than at launch. Possibly when you make your first move. I might even follow David's advice and make it something you explicitly enable.