As shown in that article, and the follow up post in the forums, it is ALL about how far away you will be sitting vs. the size of the display, combined with the source material - and a heap of how good your eyesight really is.
Bottom line for most people is that 720p or 768p is fine for them.
I'm likely going to get a 1365x768 plasma as my next one because the price is better and Pioneer plasmas have better color, image processing, and contrast levels than most other displays on the market.
Go cheaper, but get the better contrast/color/processing.