One of the most heated debates amongst the fan base is the argument of Rockman X's true identity: Is X the same robot as Classic series Rockman or is he a separate individual bearing the classification of a "Rockman?"
Although no outright answer has ever been given by Inafune san or the games themselves, the fact that official sources dodge the answer to the question is proof in itself. Various source book material constantly refer to X as a separate character, going so far as to establish his own unique set of schematics that greatly differ from Classic series Rockman. If the two were indeed the same character, source books or official supplemental material would have stated so by now.
One of the most intriguing pieces of information supporting the theory of X as a separate character comes from the official Japanese Rockman forum. Years back, a user asked Capcom staff if "Rockman, Rockman X, (and Rockman Trigger)" were the same character. To everyone's surprise, Rockman series staff jumped in and answered the question: All three Rockmen were each separate characters. Interesting yes, but should we take this answer literally? It's debatable.
Like the former "cataclysm theory", this debate will continue to be waged until the day Inafune san himself gives a definitive answer himself.
Until then, let the speculation continue on!