XRP is a silly name and Ripple will fail partly because of that. Sounds like something a 12 year old came up with.
ISO 4217 requires that currency designators be three-letter codes and that designators not issued by a country start with the letter 'X'.
http://en.wikipedia.org/wiki/ISO_4217Tha's really interesting. It seems, creators of bitcoin didn't bother about following the standards but those of Ripple do. Another example of more professional approach of Opencoin guys.