I think we (Aruba) unintentionally invoked confusion by releasing an IAP product called a "RAP" which is not to be confused wiht a 'Remote-AP" that is used to connect to a traditional Controller. Any campus AP can be deployed as a "Remote-AP", but as my colleague Marcus articulated, our RAP3, RAP108/109 and RAP155 are IAP's by default...but to confuse matters can also be depoyed as a 'Remote-AP' connected to a headend Aruba Controller.
Think of it this way, IAP's are the new Remote-AP's but don't have the same limitations as traditional CAP's deployed as Remote-AP's lol :)