As long as WWE utilizes the talent right. Guys like Bobby Roode, James Storm, AJ Styles, Matt Morgan, and a couple of the X Division guys would do well. That's provided they don't get buried in a stupid "Invasion" storyline.
They buried the WCW guys with that storyline 11 years ago. It can always be profitable. Some of the TNA guys have some hefty contracts, while some don't. Jeff Jarrett would be gone, as will guys like Abyss, and Garret Bischoff.
The only guy I'd hope WWE would really take advantage of is Alex Shelley. That guy can do whatever style of match possible. High flying, technical, brawling, and everything in between. I don't know if they'd pick up Kurt Angle. They might, but not at a money rate Kurt would like. He's got a ton of baggage to go with that wrestling ability.
"Now with that being said, you did a pretty good number on Paul there... But if you ever disrespect me like that again, I'll rip your throat out and choke you with your own tongue". -Taker to Big Show. 9/2/99