Yes, this a trailer for an actual movie. This isn't Funny or Die stuff, this is coming out September 3rd, 2010. (Can't say much for its box office prospects).
Let's be honest, the trailer was cut to respond to/take advantage of the Arizona Law. As quick as Rodriguez works, this had to have been in the works for the last year at least. (I've been hearing about a Machete movie since the first Spy Kids movie came out, so...)