Just under 60 at WDW, Disneyland has closer to 70.
I again heard they're reusing Splash's AA's. And some of the pieces of art previously released seems to hint at that as well. Not just the possums Janet noted, another piece of "partner" art had a couple of animals that look like possible contenders for reskins of Splash characters-
I don't know exactly how many new figures they're making. Tiana and Naveen will no doubt appear several times throughout the ride. Same with Louis. Mama Odie should also have at least one or two figures. There's over 15 new characters that will appear in both the new D+ series as well as this ride. Over half a dozen of which are probably the new human characters seen in the black and white "photo" art for the ride. So I expect those to appear at least once during the ride (if not multiple times).
There was another piece of art released alongside the one above that showed four new frog figures playing instruments, I also strongly suspect the scene and its characters will appear in the ride too. Not sure what they'd do with those fireflies though. They're small, but still large enough to possibly warrant at least a simplistic figure.
The art with the possums has quite a lot of characters present. Aside from Tiana, Naveen and Louis, there's also a spoonbill, three turtles and that new otter character. All of which seem to be new. The hanging possums are as mentioned likely returning Splash characters. There's also silhouettes of at least 7 other animals with instruments in the background, of which I am also confident will be legit AA's (it's Disneyland's variant being displayed in the art, those are likely other scenes you can see through into). Hard to say whether any of those are reskins or new figures at the moment.
The most recent piece of art from WDW's showcases a scene with 11 AA's in total, a larger quantity than that scene previously had as Splash. I'm also not sure if any of the figures present are reskins. Tiana, Louis and the Otter are definitely new. Likely the turtle as well. The frogs also have very different and more unique designs than Splash's, so I don't know if they could possibly be reskins either. The rabbit and racoon COULD be reskins, but i'm not even confident in assuming that. Quite plausible that all of these characters are new.
I will also mention in passing that models for the front of the mountain also have two frog figures on a log. I'm not really expecting these to be AA's given that they're exposed to the elements, but we'll see. I expect them to be stationary, or perhaps a more simplistic design with basic motion.
I don't know if there's going to be 48 new figures, seems like it would be high for modern Disney standards, but there does appear to be a lot. So who knows. It also seems like they're handling this ride quite differently to how they've been doing things over the past 20+ years...