"If I was a CIO, I'd be asking for a more detailed road map on what is and isn't supported before I'd commit to deploy Windows Phone," Greengart said.

The other major issue is the level of application compatibility. "There will be some compatibility. The question is how much," Greengart said.

Microsoft recently said in a blog post that "today's Windows Phone applications and games will run on the next major version of Windows Phone."

The company also said that "all" of Windows Phone developers' programming skills "are transferable to building applications for Windows 8, and in many cases, much of your code will be transferable as well."