Screamscape has had it rumored for awhile that CW is getting another large coaster for the 2015 season (Assuming Sky Rider is finally getting the chop), and they're usually very accurate! So it would make sense budget-wise that they would be putting in a Dark ride attraction if the 2015 rumors are true.
Lance (Screamscape) gets his info from right here on CW Mania. A few days (or even maybe the day after) kunpc1 mentioned possible TLC/new slide for Splash Works, Screamscape had it. Then, as soon as Mamba was trademarked and mentioned here, Screamscape had it within 72 hours. Finally, when someone mentioned SkyRider possibly being removed.....you know what happened.
Also, I emailed Lance and it turns out the Thunder Run rumor was his idea. He thinks that the dragon scene in Thunder Run can be better used with a dark ride.
Finally, it doesn't look like Breakfast Television will announce the new ride....CW just sent out an email saying they will announce it on Facebook.