I doubt you'll see one that can run any desktop app. But Universal Windows Apps? Many will run on Win10 today. The developer has to specify the phone as a runtime target.
>If I see a Microsoft Surface Phone that can run desktop windows applications I will be one of the first people in line to buy one!! I wanted to get one of these things
http://www.engadget.com/2012/03/11/itg-xpphone-2-hands-on-windows-7-on-a-smartphone/ but never was able to get one before they disappeared.
Craig Berntson
MCSD, Microsoft .Net MVP, Grape City Community Influencer