I just wanted to know whether Microsoft has dropped the Managed implementation of DirectX as mentioned here is it true?
Please if you can get any link directly from Microsoft website about the same.
Yes. The Managed DirectX development was basically stopped. You can see references to the fact that Managed DirectX 2 will never ship on blogs, etc, and it was pulled from the DirectX SDK.
There are better options - SlimDX, for example, wraps all of the DirectX/Direct3D types, including the DX10/11 interfaces. It also has a much cleaner design than the original Managed DirectX.
If you need a "Microsoft" sponsored option, you could use XNA or the Windows API Code Pack for managed DirectX development. However, neither of these options provides the full DirectX API.