Any fair evaluation of the numbers says that Apple's (AAPL 0.51%) iPad is the tablet to beat. But Microsoft (MSFT 0.46%) may have already found a winner in the new Surface tablet. According to Mr. Softy's retail website, the $499 edition of the new Surface, due on Oct. 26, is already on a three-week back order.

Source: Microsoft.

To be fair, the appearance of a backlog isn't the same as an actual backlog. Microsoft could be keeping inventory precious in order to artificially stoke demand.

But that's also a cynical take. The other possibility is that businesses are generally interested in the Surface. After all, Microsoft is selling the device with a choice of keyboard-embedded covers that, for about $100 more, transform Surface into a lightweight laptop that runs Windows.

Therein lies the potential advantage -- and danger. Whereas the iPad has done nothing to cannibalize Apple's sales of laptop Macs, Surface could very well threaten Ultrabook sales in which Intel (INTC 0.61%) has placed so much faith, yet which have failed to bear any meaningful earnings gains.

Microsoft isn't the only one exploring ways to profit from offering a convertible PC-tablet experience. China's Lenovo -- one of only two global PC manufacturers to ship more units during the third quarter -- is making a line of convertibles in time for the holiday season.

Surface is more of a de facto convertible, since the only PC part that ships with the device is a keyboard, and even that's an option. Nevertheless, in offering it, Mr. Softy appears to be addressing a potential need that Apple has refused to even explore.

My colleagues aren't as sold on Surface as I am. Fellow Fool Evan Niu sees Microsoft taking a hefty writedown due to its inexperience managing inventories. Senior technology analyst Eric Bleeker says Microsoft has already bungled the launch with its pricing plan, hurting chip partner NVIDIA (NASDAQ: NVDA) in the process.