I'm sure there is someone on Aikiweb with a more authoritative answer, but when Ueshiba started teaching, he taught Aiki-jitsu. Some of the original names seem to be kept by Yoshinkan, but they are very similar (I think they call ikkyo, ikkajo). Many of the original names for the techniques in aiki-jitsu seem to be more complex, though they are often similar to what we call them now. Even after Ueshibas death it seems the names continued to change, with kokyu-nage and sokumen irimi-nage getting swapped round.
At the end of the day, the names are just descriptions in Japanese (e.g. kote-gaeshi - wrist twist). I do like the way we keep the Japanese names, since aikido is a global phenomena and we both instructors and students often travel to other countries to train (and therefore we can pretty much understand each other).