Yes, it is true, SPLASH IS OPEN. We had such a good time. Just returned this week. Went on Splash over and over again. FastPasses are a must, on Saturday the longest wait for Splash was 200 minutes. At 2pm, when I got fastpasses, the return time was between 10:55pm and 11:55pm. When we returned for the fast passes, there was still a huge line.
Since there are now 5 individual seats, and most people travel in 2 or 4, they do single riders now. Approach an attendant outside the ride, get a single rider pass, and go up the Exit. This will get you on the ride an hour or so quicker.
During last week the average wait time was 45 minutes, but Saturday was a zoo, and it went up to 200 minutes.