I'm another on the list of those patiently/impatiently waiting for ATV to support Atmos. I have a 5.1.4 system at home that I love. I'm picky about what films I buy because I don't want my physical collection pushing too far over 300. I think it's a huge shame renting films (through the ATV) with 5.1 sound when a decent atmos track exists for it, but there's no way to rent physical these days, so I'm forced to buy a copy then trade it on, which costs a lot more than a rental.
Practically every film is released with an Atmos or DTS:X track these days, so it's weird to be so behind (even if only a small amount of us currently have a capable system).
My question though, is; if when Atmos is supported, would DTS:X be too, or are they completely different beasts? Would be weird if I could stream a Star Wars film with atmos (when it does happen), but still had no access to Jurassic Park's new DTS:X mix for example.
Probably not, since the Apple TV doesn't support any other DTS formats either.