The story, which quotes an unnamed "developer who has been briefed on the project," has been greeted with some skepticism. So much so that MTV posted a FAQ on the story earlier today -- an interesting, and I think, effective way to address criticism and questions lingering around the report. They provide some additional detail on how they reported the story and why they dropped it now:

-- MTV has been "doing background reporting on this story for several months, but only recently felt the facts were solid enough to file a report." In the original story, MTV's source says the Microsoft controller could be out by the end of the year "if everything goes as planned."

-- Responding to criticism that this story relied on a single, anonymous source, MTV said it confirmed "with at least two other high-level individuals in the gaming industry that Microsoft has been developing motion-controller prototypes, even if they hadn't seen this particular prototype firsthand. Other sources said they had heard rumors of varying degrees -- Rare's involvement, a Wiimote-like controller -- and didn't have firsthand knowledge, but their details supported our primary source's claims."

Microsoft is not commenting.

Nintendo's simple intuitive, controller has made gaming more approachable to millions of people -- which, in turn, has made the Wii the fastest-selling console in recent months. It's poised to overtake the Xbox 360 in total U.S. sales later this year, despite the Xbox 360's full-year head start.

I spoke with Nintendo of America President Reggie Fils-Aime at a lunch with several reporters on the sidelines of February's Game Developers Conference in San Francisco. He was asked about rumors that were circulating then that both Microsoft and Sony were working on motion-sensing controllers.

"They will need to have software to support it because again, the gaming industry is littered with one-ton peripherals that never go anywhere," Fils-Aime said. "And so the question would be, what's the game content to support it? Who is it marketed to? Does it fit with the overall proposition of the box?"

I asked him whether game developers who have made games that take advantage of the Wii's motion-sensing remote would be able to easily port their games to a hypothetical motion-sensing controller for Xbox 360 or Sony PlayStation 3.

"Well it depends on how their peripheral works," he said. "If it works similarly than you could make the argument well, maybe it's easy to port. But then, OK, is [game publisher and developer] Take-Two [Interactive Software] going to take 'Carnival Games' and port it over to 360? Do they think there's a market? Does it make business sense? I mean, again, it becomes a really tough question as to whether or not the developer sees it in their best interest to make that kind of port."

Even if Microsoft is on its way to market with a Wii remote competitor, Nintendo is poised to pull ahead again with the Wii Balance Board, due to launch in the U.S. on May 19, along with the Wii Fit software. A player stands on the weight-sensing balance board and completes a series of exercises, including yoga and other disciplines.

Thanks to Crave for the link to the MTV story.