If a new Kindle were large enough and cheaper, it might make the cut. But I'm highly skeptical as I don't see Amazon changing its tactics and permitting folder structure, full non-DRM support, open firmware etc. Its possible than Amazon may never get (or acknowledge) the fact that many people wanting to use a large e-ink reader already have (*ahem*) content for it. They will probably sell DRM'ed textbooks online.
The Plastic Logic is a possible replacement (WinCE, while no less than an abomination, probably allows folder structure and third party apps), but then again, who knows? For now, I completely agree that the DR wins. Some of the "annoyances" described in the previous posts have actually been addressed (at least indirectly) in firmware 1.5.