Two tablets currently (three if you count the Xoom I just transferred to my parents), my last three phones, two laptops (work + personal), Roku 3, and I believe even my TV (Panasonic VT60) have all supported 5 GHz. At this point virtually everything I have that is used regularly is 5 GHz. The only things that don't are my PS3, 360, and Kindle.
So currently in use I guess that makes 7.
On a side note, I hope there is a special place in hell for the Roku designer that decided to make the wi-fi direct remote frequency hop to chase the wireless network it is connected to for data. One of these days I'm going to go buy a good 5 GHz bridge to use for all my entertainment stuff mostly just so I can lead the Roku to clear spectrum and ditch it there by putting it on Cat5. It annoys me to no end that the only other 5 GHz AP I see is my Roku sitting directly on the frequency my Ubiquiti AP is using.
Viper GTS