Have you tried 3d in 48hz mode? This is only an option for 24fps content, but it does, indeed, reduce crosstalk somewhat, as I can attest to this from seeing the ST30 last year. However, the flickering in this mode in brighter scenes, at least on the ST30, made it unwatchable for me.
Alas, someone in the UT50 owners thread mentioned they didn't notice flickering in this mode and it made a significant difference in reducing the amount of crosstalk they saw, so maybe the flickering is tolerable for some people in this year's panasonic plasmas... who knows?
Obviously, Panasonic's focus is on 2d picture quality, and understandably so, since that will generate far more sales and interest than an improved 3d picture would at this point in time. Really sucks for those of us who detest even the slightest bit of crosstalk and prefer plasma to, say, this year's passive LG's or a DLP setup.
Anyway, though, it really is surprising they couldn't at least improve crosstalk to compare to Samsung's plasmas!