Wow, this thread makes me feel old compared to the rest of the fanbase, haha. As Dunsparce said, there was an old event for Pikachu with Fly in the 1st gen (though it might have been Japan-only), and the TCG card looked like this:
http://www.virtualgulfcoast.com/pokemon/images/pikachu-flying.jpg
See the balloons and stuff?
Granted, there was never an anime episode about it like Surfing Pikachu, but it did have a part in the manga, and there were at least two events in the 3rd gen with flying Pikachu (Japanese ANA and American Bryant Park), though you couldn't transfer the moves due to the HM rule, and unlike the special one with Surf, it hadn't been available in the 4th gen (until now, I suppose).
Anyways, I'm excited to see it come back. I'm a sucker for special/exclusive moves, so I love that it can learn Fly again, and I'll be sure to get one, even if all it does is sit in my box. :P