An update to Visual Studio 2013 is now available for download including updated DirectX related features.
For more details see Visual Studio Team Blog, Brian Harry’s blog, and Somasegar’s blog.
Official KB article 2927432
VS 2013 Update 2 includes a new version of the C++ compiler (18.00.30501.0). There's no new C/C++ Runtime--it still uses CRT version 12.0.21005.1 from VS 2013 RTM), but there are updated remote debugging tools packages.
This compiler update includes a new /arch:AVX2 compiler switch.
Windows phone: VS 2013 Update 2 includes the Windows Phone 8.1 SDK.
Related: Visual Studio 2013 RTM, VS 2013 Update 1, VS 2013 Update 3, VS 2013 Update 4