Thanks for all the comments.
Graham is right that 10" and lowest resolution I gave is probbaly too low. Although I wouldn't mind high dpi, if there's enough pixels otherwise and not a huge battery drain.
I looked at something like WeTab today:
http://wetab.mobi/en
It's basically a mediatablet, competing against iPad and the same screen/battery issues remain. So not really a good read after all.
The same issues plague device like ICD Vega:
http://convergeddevices.net/products/vega.html
Notion Ink Adam (also low-res)
http://www.notionink.in/
Entourage Edge
http://www.entourageedge.com/entourage-edge.html
All have a glossy unreadable screen and battery life usually below 10hrs.
Of course, they are all expandable, hackable and will in the end support most formats.
I see the market currently developing towards full-color media/pc tablets at sizes from 7" to 11" but with fairly low resolution.
Then the actual reader market seems to be concentrating on the pocketbook sized (7" and smaller) currently b&w (soon color) eInk type book readers. Again with fairly low res.
All the big and more high resolution b&w ebook readers seem to be dead, postponed or in limbo.
Surely there is a market, if only within the group of all university students for c. A4 sized high-res ebook reader with open format support?
Is it just a technology thing that no such displays exist?
Well, I'll keep looking and trying to resist the lure of DX graphite, which I can't even get with proper recharger for my region. Sigh.
EDIT: Oh, almost forgot.
The new Pocketbook Pro 903 does indeed look quite promising. Personally I'd still prefer a higher res, but it is the best so far that I have seen, has pen input and is not vaporware