The DVDO Quick6R supports 4K switching and has MHL support.
This stylish switch box could be the center of your home theater source and display switching. It should be equally competent as a small commercial switcher. DVDO has been making the Quick6 for about 3 years, more recently adding MHL support (the R in the name).
The key capability that got my attention is that it switches 4K material. That's what I was looking for, but there are limitations. Let's get started!