hummm...
I've played with the idea of rooibos espresso but I can't get mine to look as thick or rich as theirs... 
Yum, go to the website they post at the end of the video. It seems that what they sell is basically just plain rooibos that they've ground. It'd be easy to make with a coffee grinder. I've never made espresso though but it definitely sounds interesting. I've really started liking rooibos a lot and this sounds delicious!