Yeah, just like with Amazon, this sets a bad precedent. Send the user an alert that their app has been "recalled", and present them with an option to remove it immediately. Also, in the marketplace or app listing, mark the app as recalled (in case the user dismisses the first warning). However, nothing should be removed without user consent unless it is so malscious as to be causing actual harm to the customer.
"That poker game you downloaded has been sending virus emails to everyone in your contacts list, so we disabled it"
not Apple-style: "We didn't see a point to it personally, so we made the choice for you and removed it."