Well "Golden Boy" John Cena wouldn't have become relevent
Chavo guerrero probably would have became a world champion, seeing as he had just had a huge feud with shane helms before WWE bought them out.
Eric Bitchoff (no thats not a typo) would be regarded as the "mastermind" that won the monday night wars, and Garrett would have been shoved down our throats a long time ago, that 150 lbs. sack of crap would have had a undeafeted streak that would outlast both goldbergs and Crimsons.
Speaking of Goldberg, he stays relevent till 2005 or around there, then retires like he did at WM XX.
TNA is never created, because its founder, Jeff Jarrett, stays with WCW and becomes a multi time heavyweight champ. Cheating us out of stars such as AJ styles, Austin Aries, Bobby Roode, James Storm, Samoa Joe and so forth, however I would assume sooner or later they would be signed.
Cruiserweight wrestling becomes huge, seeing as WCW started it, the Cruiserweight title becomes a world championship, and cruiserweight wrestlers are treated as secondary main event players.
Also, I would assume WCW would pick up 25 contracts from the WWF so this is who i think they would have signed.
The Rock (never worked for WCW)
Stone Cold (Yes, i know Eric Fired him, but Austin became established in WWF and Eric would Capatilize.)
Undertaker (Worked as Mark Callous before WWF, would have a undeafeted streak at Starrcade.)
Chris Jericho (Heart and Soul of Cruiserweight divison)
Jeff Hardy (Daredevil originator in WWF, would eventully become WCW world Champ)
Matt Hardy (See Above)
Christian(See Above)
Edge (See Above)
Triple H (Worked as Conniticut blueblood, head of WWF stable in WCW)
Billy Gunn (Never worked for WCW, becomes tag champ with RD)
Road Dogg (Never worked for WCW, becomes tag champ with BG)
X-Pac (Worked as Syxx for NWO, would rejoin and become Cruiserwieght champ)
Chris Benoit (Was WCW champ, day before he walked out, WCW wanted to keep him, would stay on top of card for a LONG time.)
Eddie Gurrero (Worked well for them, hes EDDIE he would get signed back)
Besides them i dont know who would fill the last spots but it would have been pretty damn good and pretty damn intresting