true, more pixel density of Full HD will always be an asset to your TV, in my view anything above 32 inch should be Full HD....
avfactor - HD ready is usually inferior to full HD LCD.
What HD ready typically means it the TV is capable of playing HD signals (720p/1080p etc) but the catch is the display resolution of the screen could be 720 or even lower - it depends on the model/manufacterer and we dont have standards for it.
So my suggestion would be to wait for the full HD.
Have experienced both plasma/LCD 46 screens, plasma guess does produce better black levels and has some + points. But LCD sure is coming very close. The things in favour of LCD would be the longer life (LED driver back panels) and lower energy costs compared to plasma and is a bit less fragile than plasma.
Yes panasonic is the best with plasmas.
Best wishes.