Now I don't want to start any fights or ruin anyone's day, but before you drop $1.5-3k on a new E-series plasma, for the love of God, look at them hard in the showroom
. Yes, I viewed them in the store, but it was in Best Buy's "Magnolia Room", where the lights are very dim, and I would argue it's not a bad test environment. I got to play with the remotes and I can tell you, when the E-series and D-series are literally right next to each other, I can't tell any difference between luminance, black level, or picture clarity. They appear exactly the same to my eye. I even had a hard time identifying which one was the E and which one was the D at first. Now they DID look slightly different, especially in the white balance, but this was clearly due to a lack of calibration. Some of the E-series looked slightly better depending on screen size, for instance.
The E-series looks like a great set and I'm still considering buying one, but moving from a D-series? You're going to be disappointed, unless you're looking for the added web/control features (which aren't much to write home about, in my opinion). PQ-wise, this is barely even an evolutionary upgrade. Far from the "revolutionary" upgrade of Panasonic's ST30->ST50 this year, for instance. You aren't going to see a jump like that by any means.
As for E8000 vs VT50, it's becoming more clear to me that this year Samsung upgraded its gadgets, while Panasonic was all about PQ.... in some cases hopefully catching up to Samsung (motion resolution, color accuracy), though we only have the early indications from the mid-range ST50 to go by at this point. I stopped by the VT30 in the Magnolia room to compare as well, and it's still a great contender. So good in fact that I don't think I could throw down $$$ on an E8000 until I see what Panasonic does with the VT50.