Well, iRex says, that the DR1000S is capable of a proper power management, but the software is not ready yet. We will see, if they can deliver a proper pmm i a few month i think.
The Plastic Logic reader is announced for Q2 2009. But if they are anything like all the other companies, that bring out completely new technology, i assume it will be Q3 2009.
I personally like the DR100S sofar, but i really hate the short battery life. On the other hand, i am using it and dont want to miss it, in spite of the bad runtime.