That is such a smart design (using mirrors to focus sunlight onto one point rather than using lots of solar panels spread about). How long have scientists had this idea?
Two millennia or so. Power generation has always been applying new ways to boil water (save wind and hydro).
I am actually disappointed in the video. There were no 3d models, and the project talked very little about the engineering effort. Instead we are given very stoic music and a bunch of PR.
http://select.nytimes.com/gst/abstract.html?res=F40A10FB3854...
http://news.bbc.co.uk/1/hi/sci/tech/6616651.stm
but the idea is as old, Archimedes is said to have used mirrors to set fire to a roman fleet.
Also, to the sister post, there are relatively few moving parts in the collector itself. Furthermore, these are all conditions that we've dealt with already with traditional turbine systems (they get pretty hot too), and aircraft design. The harder part is getting the sun tracking right. The Seville (and I guess this one too) plant actually has to point a bunch of mirrors off the tower (they park them into a tower of light above the tower... looks really cool) at peak, since it actually gets too hot (it would melt concrete or something ridiculous I heard...)
The main difficulty is maintaining a high temperature system with lots of moving parts, but in that respect it's not much worse than a fossil fuel plant.
Edit: not forgetting the usual source reliability / distribution problems for renewables.