So, John Scalzi's forthcoming book, Redshirts is pretty excellent, from what I've seen of it. (The first four chapters are available online as a preview.) In a nutshell, it's "Rosencrantz and Guildenstern are Dead," but for Star Trek instead of "Hamlet." So when Jonathan Coulton wrote a song to go with the book, it was only a matter of time before someone mashed it up with actual footage of redshirts* meeting their various and inevitable ends.
Anyway, if all that doesn't make you immediately want to watch, or if you're about to leave a comment asking what, exactly, is a "redshirt," then you probably should just wait for the next post.
*Caution: that link also includes a video of Scalzi covering the song on a ukelele, for which I refuse to vouch.◼