So we all know Uncharted is a great success for PS3, so why not a game series on the Firefly franchise? You could have a 3rd person cover based shooter with mechanics like Uncharted based upon Malcolm Reynolds of the Firefly series, plus you could mix it up with melee sections playing as River Tam.
The universe would allow an immense amount of creativity as you could pick your missions on Serenity as Malcolm and select different missions on different planets. This could allow for a wide range of different planets and scenarios, such as stopping the Alliance on a developed city planet to stopping a reaver raid on a out of the rim outpost. The possibilities creatively are really quite endless and allow a lot of freedom.
All of this would close up the storyline between River Tam and the Alliance story arc and allow some closure. Plus if you could get the original actors to do the voices that would make it all the more awesome.
I just think that there is so much missed potential on this great franchise.