Exciting stuff, Soma just announced the availability of the release bits for Office 2013 development with Visual Studio 2012!

http://blogs.msdn.com/b/somasegar/archive/2013/03/04/now-available-office-developer-tools-for-visual-studio-2012.aspx 

This impacts a huge number of our corporate and enterprise developers, who are consistently tasked with bringing the next great set of business capabilities through custom applications to their users. These tools represent a complete set of capabilities for developers to develop, build, test and deploy great Office and SharePoint applications, both on-premise and in the cloud.

To learn how to get up and running quickly with these new bits, be sure to check out some of the great resources available at http://msdn.microsoft.com/en-US/office/apps