Are Windows Phone 7 slates waiting in the wings? Don't get your hopes up

Windows Phone 7 phones are coming, starting next week in Europe and November 8 in the U.S. But what about slates running the Windows Phone OS 7 operating system?

There are slates out there running Apple's iOS phone operating system (the iPad) and various slates based on  the Android phone operating system. So what about the Windows Phone 7 operating system? Is there a secret Windows Phone slate waiting in the wings?

Microsoft officials said no earlier this year. And after asking around this week at Microsoft's Windows Phone 7 launch and Consumer Open House in New York, I'd say the answers still is no -- at least not in the foreseeable future. Too bad, as some of the elaborate mock-up concept videos and screen shots for a Windows Phone slates we've seen look pretty darn compelling.

Microsoft is restricting its partners from putting the Windows Phone OS on certain form factors by limiting device screen size. The roughly 4-inch phone screens on Windows Phone 7 devices are the biggest that Microsoft will allow to run the Windows Phone 7 operating system, I was told by Microsoft officials this week.

Microsoft allegedly did the same with Windows 7, as some may recall. Microsoft made changes to the maximum hardware specifications allowed by OEMs who wanted to preload Windows 7 Starter and Home Basic. (Supposedly 10.2 inches -- measured diagonally -- was the "defining boundary" between what constituted a "small notebook PC" vs. a "full-featured laptop.")

That seemingly means that any PC maker who wanted to tweak the Windows Phone 7 OS to run on anything bitter than a phone screen would be barred by Microsoft's licensing terms and conditions.

So manufacturers who want to offer "Windows slates" have two choices: Preload Windows 7 or preload Windows Compact Embedded. While it is true that Windows Compact Embedded is the same "core" which Microsoft tweaks (heavily) to build its Windows Phone operating system releases, it's highly doubtful that any OEM would be able to "recreate" the Windows Phone OS itself on top of the same core without violating Microsoft patents and licensing rules. In other words, while some slate maker possibly could make its device look and feel similar to the Windows Phone 7, but it wouldn't actually be the same operating system.

Could this all change at some point? Maybe. Microsoft could remove the restriction on screen size if company officials decided that would be advantageous or necessary. Additionally, Microsoft did sign a deal with ARM earlier this year that set off speculation that the company will -- at some point -- release a version of Windows (and not just Embedded Compact) that can run on ARM. And then there's the whole Project Menlo work happening inside Microsoft Research. Could that lead to the arrival of a Windows Phone slate someday? Who knows....

If you could buy a Windows Phone 7 slate, would you? After getting some hands-on time with the Windows Phone 7 devices this week, I, for one, would be very interested.