I don't know about the others, but I chose Rachel as my main because of her character design (though her CT playstyle is fairly awesome). If her playstyle changes, at least I still get to have the same lo--.
Now, if they suddenly made her into an adult, then I'd be really annoyed.
Anyway, it's sort of hard to say how things will change, at the moment. I mean, it's still possible to cancel j.2c into 214b for the pumpkin (though it's apparently slower to come out, now?), so air combos don't seem to be taking too large of a hit outside of the loss of j.2c -> j.c.
If they actually nerf out j.2c, I guess there'll be a lot less rushdown and a lot more pumpkin and seeding going on. I'm assuming that's why they added the aerial Sword Iris, sped up the aerial BBL, and made it possible to activate the poles before they fully form. Doesn't really explain the pumpkin nerfs, though.
The frog speed nerf barely effects me, to be quite honest. If I toss him out randomly, it's just because I want him to be between me and my opponent. I don't really care too greatly exactly how fast he moves towards them, and as the frog combos still work, it's hard to complain. The timer is a bit irritating, seeing as how it's no longer possible to combo back into a frog from a frog->super, but meh. I can live with that.
I do wish they hadn't nerfed BBL's base damage and made George pro-rate it to nothingness (300 damage from a BBL, really?), though.
Mostly, I just want j.2c to cancel into something useful... though, if they give us some better zoning stuff, I guess I'd be okay with that, too. I'm just addicted to j.2c.
Somewhat related, but does Rachel fall during her aerial Sword Iris, or does she just hover in place? Was wondering if it'd be possible to cancel into it from j.2c near the ground. I mostly have no idea what I'm talking about, here, but it would be awesome if someone would humour me~.
/if anything seems weird, blame it on the fact that I have yet to sleep.
That's sort of the impression I have of Nu's changes. I'm still going to sub her (and Bang), because her actual playstyle hasn't really changed.