If Vince McMahon never bought WCW, AOL/Time Warner would have still gotten rid of it some how. They still would have pulled WCW Nitro and Thunder off of TNT and TBS. I think Eric Bischoff would have come back with Fuscient Media or another company and made another offer to buy WCW and I think it would have worked.
From there... who knows what would have happened. Obviously like some of you have said here I don't think wrestlers like DDP, Booker T, Steiner, Hogan, Hall, Nash, Goldberg, Flair, Mysterio, etc. would have jumped to the WWF. I think Bischoff would have found another channel to put WCW on quite easily since really back in 2001 wrestling was still very popular and he could have probably gotten on the USA Network which would have been huge.
Eric Bischoff would have then probably gone through with his original idea (like he wrote in his book) and WCW would have been off the air for a while with a relaunch date booked. He would have probably gone through this his plan to build an arena in Las Vegas (WCW was always big there for some reason) and hold all TV tapings and most PPVs there while they re-establish the WCW brand. I'm not sure who would have re-signed with Bischoff's new WCW. I'm sure he could have probably gotten Hogan, Hall, Nash, Sting, Flair, DDP, Jarrett, Piper and others. I think he also learned from his booking mistakes and would have gone back to booking WCW like he did when they were on top (from '96-'98) which would have meant to build a new cruiserweight division. I think we would have seen more wrestlers from Japan, Mexico, etc. come to WCW. The new WCW would have probably been built around Goldberg, Scott Steiner, and Booker T with Jeff Jarrett, Vampiro, Rey Mysterio, Kidman, Konnan all getting pushed. I think Hogan, Flair, Sting, Luger, Hall, Nash and DDP would have still been used a lot but not as much as they had been before with Bischoff. I don't think any of them (besides Hogan and maybe Sting) would have had more runs with the title.