Just when I thought Lucario could get anymore badass Nintendo pulls a stunt like this.

In the newest scans of Corocoro, something called Mega-Pokemon was reviled. There isn't a lot of information about it, but apparently its something that's different from evolution and forms and it's something that happens in battle with a Mega Stone. Tons of other Pokemon get mega forms (which is what Mr. Newtwo is), and they can be seen following the link below.

http://www.serebii.net/xy/megaevolutions.shtml