I don't like fandom resurrection-petitions/campaigns, and I'll tell you why:
Fans like too many characters and shows would be no fun if the good guys never died.
After last week's episode, there's a petition out there to bring back Gabriel, but as Richard himself says: Gabriel had a great exit. Yes, I was as sad as anyone that the Gabester died. I loved the character in both his forms. But after the arch-angel reveal, could he have really gone back to his role as comedic-lesson-teaching-dubious-meddler?
The only role left for the Gabriel was that of an archangel - an archangel that had to choose sides. And he did, and it was brilliant, and he went out a hero. Even if they brought him back - he would still be ONLY an archangel. Like I said - there would not be a return to the Trickster. There would only be Gabriel the archangel. The Trickster died in Changing Channels.
But that's just one case. I also don't agree with fandom resurrection-petitions because, and I mean no offense by this: JUST BECAUSE YOU ARE A FAN, DOES NOT MEAN YOU CAN WRITE! Actually, because you are a fan, by definition, you should probably not write for the show.
Fans are too attached to everyone. They are far too emotionally involved in each character to see how a character's death serves the story-arc. (And I know Supernatural has an intelligent fan-base too, but just look at the knee-jerk reactions out there and tell me I'm wrong).
It's why, although Kripke seems to have done a good job of it so far, I actually don't like the idea of the writers reading the fan message boards. I've seen enough horrible fix-its and schmoopy AUs of how fans "wish it could have happened" to know that if it were up to the fans, no one would die except the bad guys and any girl who so much as touches either brother. How boring would that show be? Good characters dying drives the plot forward in heart-wrenching but necessarily emotional ways. Annoyingly evil characters surviving for extended periods of time *cough*Ruby*cough* also drive the plot forward in manipulative but necessarily evil ways.
And this is coming from someone who not only has a tendency to fall in love with the expendable crew-members on most shows, but also gets HEARTBROKEN when their favorite characters die. Seriously...I go through all stages of mourning.
The other problem with resurrection-petitions is that not everyone agrees on who they like. Everyone in Supernatural seems to like the character of Meg. Personally, I couldn't/can't stand her (exception was when she possessed Sam - that was cool). I was really happy when she wasn't around anymore. I don't mind so much that she's come back, but I still don't like her and I'm glad she's only shown up again twice. On the flipside (if there were such things as Death-petitions), you wouldn't have much of a S4 plot without Ruby. I loved Ruby for how questionable her motives were, how evil her little self-satisfied smirk was...I had to agree with her at the end, she WAS awesome. I actually think I developed a crush on Genevieve, just because she drove the plot so well (and seriously, her evil smirk is just amazing)...I am WELL aware of how much in the minority I am with those feelings. I would very much prefer to suffer at the whims of a capricious writer than to suffer at the hands of an overwhelmingly biased fandom. (Because, let's face it...would fandom hate Ruby/Gen as much if there had been no romantic connection with Sam/Jared? Wouldn't she have been another Meg character then? Meg...who fandom seems to adore at least in Nikki-form?)
The only reason I worry about certain deaths is the limitations it puts on the writers' sandbox...but again, the writers haven't disappointed me so far, so there's no reason for me to stop trusting them now. And having too much in the sandbox has always been more detrimental to creativity than having too little.