Retail SDK project unavailable

If you're getting errors similar to the below when open up the Retail SDK solution file, that's probably due to the Visual Studio 2012 Office Developer Tools is not installed yet.
(Ref: http://blogs.msdn.com/b/somasegar/archive/2013/03/04/now-available-office-developer-tools-for-visual-studio-2012.aspx)

Download the web installer and get it installed, then reopen the solution file, it should be fixed now.

Sample error message:
Unsupported
This version of Visual Studio does not have the following project types installed or does not support them. You can still open these projects in the version of Visual Studio in which they were originally created.
 - SharePoint.Web.WebParts, "C:\Retail SDK\Online Channel\StoreFront\WebParts\SharePoint.Web.WebParts.csproj"
 - SharePoint.Web.Storefront, "C:\Retail SDK\Online Channel\StoreFront\Storefront\SharePoint.Web.Storefront.csproj"
 - SharePoint.Web.Scripts, "C:\Retail SDK\Online Channel\StoreFront\Scripts\SharePoint.Web.Scripts.csproj"
 - SharePoint.Web.Services, "C:\Retail SDK\Online Channel\StoreFront\Services\SharePoint.Web.Services.csproj"
 - CommonGlobalModules, "C:\Retail SDK\Online Channel\StoreFront\CommonGlobalModules\CommonGlobalModules.csproj"