First of all, let me wish you Merry Christmas (ok it is not Christmas, but is still kinda you know?):

This video was discovered surfing about another great video, this one:

Watching the first time was absolutely awesome, the second was brilliant, and the third, well, I need to find out more!
Fortunately following the link I stumble upon (sorry -.- ) a video response:

Reading the comments I figure out the whole story behind them. And at last I came here

The moosebutter group ©moosebutter

The moosebutter is a group of 4 acappella boys (read more about them in their website). Corey Vidal (the author of first video) aske them the permission to make a video using Star Wars theme.
After the planetary success (more than 3,000,000 of views), the original performers made the second video as response (render unto Caesar the things that are Caesar’s). That’s all!
[original story]