According to Kotaku, a Source, that prefered to remain unknown, revealed that the controller for the next Xbox Console won’t be much different than the one from Xbox 360. So the controller might be very similar by the way it was described, but it might be a bit smaller. However, nothing of this was oficially confirmed by Microsoft, so the Source itself didn’t say much more.
Microsoft also took some precautions against possible leaks and each development kit has controllers with decorative ribbons, which means that Microsoft will know which studio is responsable for any image leak on internet.
In the meanwhile we expect a Microsoft conference soon to reveal the next Xbox console, as every information, including this one, is nothing more than rumors, which means nothing is official.