Just played Black Ops 2 last night on the 60st60, going from a 55st30, there is definitely an input lag difference, you can tell because it feels just like I'm playing on my friend's LED TV. It's very slight and takes some getting used to but it's definitely there, it's disappointing that Panasonic would screw this up, Plasma is usually perfect for gaming, but it's not a deal breaker for me.
As far as settings go, I'm using D-Nice settings with the GAME mode turned on, all the extra crap is disabled. If I'm not doing something right, let me know.
Hopefully it's a software fix, but judging from previous years major Panasonic problems (Floating/rising black levels), I doubt it.