а) They are all 6-bit (TN, 19"...).
b) There's no method to determine is panel 6-bit or 8-bit.

That is not true. HP LP1965 uses an 8-bit panel and therefore is the only monitor in this latest round-up able to display 16.77M (16,777,216) true colours, unlike the others that can only display 262.1K (262,144) non-emulated colours.

Sorry, missed it.

But, you can't say that others display only 262k colors. There's no "emulated" or "non-emulated" colors, otherwise you should say that all plasma panels can only display 1-bit color (other colors are "emulated" by high-frequency modulation of gas discharge in sub-pixel plasma cell) :)
They display 16.2M colors.

TFT-LCD and plasma use entirely different technical methods to generate colour, as you also understand them yourself, with the latter being capable of displaying billions of colour with ease, and therefore should not be directly compared to one another in terms of number of colour bits supported.

Given what we know, and limiting the discussion for the purposes of the article, a number of manufacturers have been intentionally misleading consumers by attempting to make an 1:1 comparison between 16.77M true colour 8-bit panels (2^24) and supposedly 16.2M 6-bit panels (2^18 = 0.262M in actuality), and so it is up to (I am counting on) reputable sites such as X-bit labs to keep the best interests of their readers in mind by keeping the vendors honest with their specs.

Prices are not the same in different countries. For example, Dell 2407WFP-HC: http://www.behardware.com/html/news/cat22/page1.html#90 7

It will be ready next month.