How to see who else has iMessage?

Ok, so if I go to message, and then go into my contact list, how do I actually find out who else in that list has iMessage? From the look of things, I can only find out once I click on their name to send them a message. Surely it makes sense to be able to see within the contact list who else actually has it, or I don't know who I can send one to.

Or am I missing something?