My two cents: if you see it showing up on the phone and are sure you added all the icon/artwork files in there, you probably have nothing to worry about.
Optionally, you could see what results you get with the Xcode->Organizer->Archives->YourApp-> "Validate" button,
or
You might try submitting it to the app store with the "Wait-until-I-tell-you-to-publish-it" (paraphrased) option checked, and see what it looks like in your itunes connect account. If you see the icons/artwork there and all looks dandy, you should be good to go. That way if anything looks funny, you can resubmit the icons ( I believe you can just do that as meta-data and not an entire binary ) before it goes live.
As a side note, I'm fairly positive iTunes would most likely reject and not publish an app that contained no icons/artwork.
Hope that helps.