I'm almost positive the nerf bat will hit Diana after her showing at IPL5. Hopefully Kat too, since the only reason she isn't played more than she is now is almost entirely thanks to Diana bullying the crap out of her, and I think her whole "spam everything on CD cause no mana low CDs lawl" playstyle any idiot can pick up on is kinda crappy. I still can win my lane vs her as Fizz even with my bugged/UP E, but even for the clearly nubby Kats I have to do some serious baiting since they can just stay in lane forever and throw knives/run away otherwise, which is pretty damn infuriating, not to mention I have a much worse time with most other toons.
I can't tell when if they are going to do a bunch of minor tweaks or a massive one though, since I haven't been playing very long. I know they are still actively watching how the new items are working out, but we will see after they have gathered enough data to start adjustments.