Here is one of mine:
E-ink, at least 9 inch or larger, high res (retina lvl or higher), fast processor, front lit, long battery life, thin and light, WITH PEN SUPPORT.
I think this kind of e reader will be perfect to read pdfs, comics, research papers. And with pen support (which allows your hand to rest comfortably on the touch screen while using the pen to write), people can also use it to take notes from lectures, to replace massive note papers and heavy binders (common, it is so eco-friendly
). Also, can you imagine, a device that not only allows you to read like on a real paper, but also allows you to write like on a real paper? I think if the cost can be managed properly, this kind of ereaders can be easily marketed to students. Lower cost, high battery life, light and thin, and paper reading experience shall give it an advantage over LCD tablet notes. Also, having an open ecosystem on this kind of ereader is going to be great, since you can have other 3rd parties to develop amazing note taking apps on this.
So what's yours?