Judging by the upvote/downvote ratio, you don't "get it", I think it's been explained, but I'll summarise;
This is a Pi project, not arduno - regardless of the competition in the "small processor board" (such as the excellent arduno/beagle etc.) the Pi has managed to be a full computer, with excellent general purpose connectivity (SD/HDMI/USB) which you can just boot up into a Linux desktop, this allows the most novice of users to get their toes wet. The thing that separates it from (say) a nano iTX or other small PC is that it's also got well thought out GPIO, which is astoundingly easy to use, loads of easy to read python. But the icing on the cake is the $25 pricetag (although we all know it's a bit more than that).
The excitement that Pi brings isn't because of what it's capable of (individual projects can do the same) it's the fact that Pi is "mainstream" - ordinary people know what it is, this article isn't an instructive article for bit twiddlers (like you), it's another "look what else Pi does", it's here on the register not to instruct geeks (like the majority of ElReg readers are), but to show the geekdom world how we are going mainstream
The whole point of Pi is that kids pick it up and we generate excited kids, and enthuse a new generation of computer literate people - the 80's and 90's were fertile with teenagers cutting code, Amiga copper and blitter programmers having fun, who then went on to various techie/IT jobs, but the generation after didn't have the same exposure, just check the CV's of UK IT people, the majority are 30's through to late 40's.
Give someone a fish, and they will eat for a day, teach them to fish and they will eat for a lifetime.
Give someone a PS3 and they will shoot drug dealers for hours after school, give them a Pi they might well get excited about technology end up with an IT job which improves the industry and gets them a good income.
(not quite as snappy, but you get the idea)