It figures that they're doing this the year AFTER I'm visiting (in three weeks). Note to all Texans: you can expect lots of big things in the next 2-3 years, and you can thank me. They always add the big things the years AFTER I visit parks!

At least I'll get on NTaG (assuming nothing goes wrong with it, obviously!)
As to the new Aquatica, it sounds like they're basically taking half the old water park -- which was FREE with admission. Then adding a few new slides, which admittedly look pretty cool. And adding a bunch of upcharge stuff, particularly those very expensive cabanas that the parks LOVE to promote. (Note that they listed them first as one of the things the park will be known for!) And now it will all be an upcharge add-on. Depending on how much they are upcharging for it, I could see a lot of regulars -- who have been getting the waterpark for free all these years -- being pretty pissed. Especially if they get to the park with swimsuits and towels and stuff, ready to hit some slides, and didn't already know about it. "Wait, we have to PAY for the water park this year?!?" Sure, they'll make like it's a brand new park, but a lot of people will be pissed. It will be interesting to see if the upgrades attract enough upcharge business to counter any loss in attendance from angry regulars. I imagine so, but it will be interesting to see the affect. I mean, sure, none of the other Sea World parks have free water parks. But they also didn't have them included with admission and then later start upcharging for them. What are the odds that they'll lower the regular admission to accommodate for losing the water park with regular admission? Unlikely, I'd imagine, but it might be a good PR move to make a slight decrease to appease some people and keep some good will.
As to the new slide that travels up a wall, with airtime, it sounds like basically the same thing we've already seen with the half-pipe and tornado slides. You'll come down a steep, fast hill, then go up a wall. Nothing terribly revolutionary there, unless I'm missing something. Presumably, you'll go higher up the wall than you do on those slides, since they're making such a big deal out of it, but it will have to make up for the several turns back and forth you get on the half-pipe and tornado slides.