Okay. Basically some dude is bankrolling his own movie, set in the Firefly universe, called Lost Transmission. No characters from Firefly or stars will be part of the movie, and Joss Whedon isn't involved in any way -- and I don't believe he's given his blessing or anything --so this is pretty much just a fan film with a million dollar budget.
Honestly, I have no idea how this works. Fox owns the rights to Firefly, so it's not like this dude can says it's a Firefly movie without clearing it with them. On the other hand, if he just makes a movie that doesn't specifically mention anything that showed up in Firefly, and is essentially just another space western with the same aesthetic as Firefly, then can Fox really do anything? The only proof that this movie is a Firefly thing is because the dude is saying it is in interviews, and that's it. I don't know if that counts.
Anyways, yeah, there's never going to be another real Firefly movie. Sorry about that. (Via The Mary Sue)