Yes, they are quite nice. The gigabit switch option is a good feature to get, as it creates a reduction of 40 to 4 cables for network access.

The blades themselves use a very low voltage Intel CPU, low voltage chipset, and some other design tricks to keep the heat down and power requirements low.

280 of these in a single 42U rack are awesome looking. And as far as where they fit, they are being sold as basic servers (DHCP, static web, etc...) or as a Linux Beowolf cluster.

Though if you are impressed with these, wait until you see what is coming...