Had Eric Bischoff and Fusient Media Ventures purchased WCW (with the TV rights or some version of on another network) I believe he would have made it successful again and I believe it would still be around today. Rumour has it that the deal included contracts for the big established stars Goldberg, Sting, Hogan, DDP, Flair,Booker T, Steiner, Rey Mysterio etc aswell as those rising through the ranks (AJ Styles for one) and they apparently had already signed RVD, Jerry Lynn, etc.
With that kind of talent I think he already had who he needed to make it successful again (If players like Hogan, Nash were a problem it wouldn't matter as there contracts were done by the end of the year anyway). I also don't think the show was in the dire state people proclaimed, WCW had alot of huge names out injured (Sting, Goldberg, DDP, etc) or just semi retired (Hogan, Nash, etc) by the time that final Nitro aired. They were all still to come back and the rating the show was getting was still in the 2s (which would probably be enough in this day and age to keep it going).
I think Bischoff also would have learned mistakes from past experiences (i.e. not pushing younger players/creating new stars), the guy was seriously burnt out in 1998-1999 (it showed) and when he came back in 2000, he had to contend with Vince Russo. I really don't think his time in TNA tells any sort of story as he was in a company that didn't have the financial backing of a Ted Turner or a Fusient Media Ventures. Add to that creatively he'd beeen out of the game along time.
But most importantly he did it before, when he took over in 1993 it took him a few years but he turned it around, moving WCW tapings to Disney was a genius idea (cut alot of costs) and by the end of 1995 WCW for the first time ever made a profit. I always felt had Bischoff owned WCW (with good financial backing) that he'd have kept it in business anyway. One thing reading his book 'Controversy Creates Cash' thats clear is the man was a survivor and a very very clever man. He can adapt to certain situations but most of all he understood the business.
We will never know the answer for sure but I do feel had Bischoff gotten WCW that we would still be seeing it today.