Apple passes this stuff on verbatim to the other developer. (I have been on the receiving end myself.) If it's a mealy-mouthed pretty-please, I'm sure they'll ignore it, if they're dickish enough to name-squat on your app.
It helps tremendously if you've got a trademark for the app name (even a pending trademark) you're golden. Or, if there's any other infringement (i.e. they stole your icon, which is copyright infringement) you're in good shape, too.
Edited to add: not a lawyer, my legal advice is worthless, etc.