Well we could hope that Nathan Fillion wins the lottery and that Fox would actually sell him the rights to Firefly.
In the event that doesn't happen we can support the effort at helpnathanbuyfirefly.com or I'm sure there are facebook pages dedicated to getting the show back on the air.
Just need enough people to show that they want the series back on air. I think the people at Fox would eventually give in like they did those times with Family Guy.They should realize the show is from 2002 and it's now 2011 and it is always gaining more and more fans and that they canceled it prematurely.
As for the cast and crew they have mostly all said they are down to come back to my knowledge .