Hello Jerry. I don't presume to be able to give you the definitive, ultimate answer. However I will put a few things to you. To start with... HDMI 1.3... Any tv that has the deep colour system will need to have HDMI 1.3 for it to work, but that doesn't mean all tvs with HDMI 1.3 are compatible with the deep colour thing. Also, it is very possible that, for example a plasma tv without deep colour will display better colours than an LCD which does have Deep Colour. Many tvs might be able to receive and decode the deep colour system, but then not be able to actually display the full benefits due to restrictions with the actual screen. Also, if you have to be completely futureproofed, you will never be able to buy any tv. Having said that, as you already have a quite recent, and quite good tv already, it may be worth just waiting a little longer to buy a new tv. And, if when the new ranges come out you prefer the old range, you will probably be able to get one of the old range for a discount.
Technically the 42PZ70 doesn't do 'native' 24fps. What it will do is accept a 24fps feed, and then display it without a trace of judder. Other tvs, like for example the Pioneer Kuros have a 72Hz mode, the whole point of which is to be able to show 24fps content without judder. But if the Panasonic can do it by 3:2 conversion and still manage to not introduce any judder, then that's good enough for me. Just so you know, this is how the 42PZ70 does handle 24fps material; it converts 24Hz into 60Hz by repeating frames, some more than others ie all the odd frames (frame 1, frame 3, frame 5, etc) are shown 3 times, while all the even frames are shown twice. On lesser processing systems (in some other tv, or in an HD player), doing such a conversion can cause the dreaded judder effect where whenever there is movement the image literally judders, sometimes making you feel quite queasy. However the Panasonic range of tvs seem to be able to do this troublesome process, but without incurring any of the problems that are usually associated with this.
I hope I have been of some use to you.