If so then read this paper on Migrating your Release Preview app to Windows 8
“This paper provides guidance and tips for migrating code assets built using the Windows 8 Release Preview released in May 2012 to Windows 8. It includes porting guidance and helpful details for developers who are tasked with migrating apps from versions of Windows 8 Release Preview…”
“This document helps developers who have written apps or samples that worked with the Windows 8 Release Preview and who now must update their Windows Store apps to work with Windows 8.
The goal of this guide is not to provide an exhaustive list of changes or potential issues, but rather to point out the most relevant “gotchas.” This should save you time and get you to “80%” much faster than you would have gotten there otherwise.
At the time of writing, Windows 8 was not available in its final form. As such, the guide may contain inaccuracies or inconsistencies.”