http://blogs.msdn.com/b/officeapps/archive/2013/10/17/announcing-visual-studio-2013-rtm.aspx

Including:

• Office 365 Cloud Business App
• MVC 5 web application and SharePoint Context for app for SharePoint
• App for SharePoint remote debugging for Office 365, including
  • Workflow
  • Remote Event Receiver (RER)