I know there are movies now mixed in 6.1, but are there any movies mixed in 7.1?

I have only heard 7.1 once, and it was using a movie that was 5.1 and simulating it as 7.1, and it sounded better.

I was just wondering, because I see a lot of 7 channel amps, but only 6.1 movies, and decoders/preamps/processors.

Actually truth be known, 6.1 and 7.1 are really one in the same. while DTS calls the DTS-ES 6.1 THX refers to its THX-EX Ultra as 7.1 both include the rear channel. While some claim to provide 7.1 channels it is not a true standard and the rear channels are mono even in a 2 speaker configuration. If you go to google and search on DTS-ES and on THX-EX you will get some very good explanations of both standards.