To avoid confusion from those of us using non Windows operating systems, I wanted to post the important note on the Maya 2013 Help Documentation in regards to the DirectX plug-in avialable in the Maya 2013 Extension.
Important: To use the DirectX
rendering engine, you must use Windows 64-bit and a DirectX 11 compatible
If you plan to borrow Maya using this universal method that works with most Autodesk products: About Maya > Product Information > Borrow License, you will notice that you will not be able to render a file using mental ray.
Maya 2013 Service Pack 2 and Maya 2013 Extension have been released
Autodesk has released both Maya 2013 Service Pack 2 and Extension. All users can download the service patch from the public site while Subscription customers have access to the Extension via subscription center.