Remember that these are hint for Six Flags Wild Northwest's 2003 ride, so Tony Hawk's Big Spin did not come in to the Six Flags chain until 2007. They can still get a spinning coaster and maybe rename it to "Tony Hawk's Big Spin" in 2007 or 2008, but by the time 2011 come around they're going to have rename it "Pandemonium"!
Fiesta Texas already has Superman: Krypton Coaster, a floorless multi-inversion B&M. I doubt they would put in such a similar ride.
Six Flags New England already has a B&M floorless coaster, Batman: Dark Knight, so maybe one of two said Six Flags parks could get Maximum RPM and Led Zeppelin could be sent to Great Escape to add to their collection of used coasters!
I can't really see Six Flags buying any of the Hard Rock/Freestyle park coasters to put in any of their parks especially Magic Mountain (as if Magic Mountain doesn't have enough coaster already!).
I much rather see Cedar Fair or anyone but Six Flags buy Led Zeppin and/or Maximum RPM!