I asked a Posek from YU and he said it shouldn't be a problem to read seforim on an E-reader. He didn't explain why, but these are two reasons that one can perhaps be meikel:
- Its not really a written text. Since its just particles floating in some sort of liquid, one can make an argument that it is not a real written word. Even though the text doesn't need continued electric power to stay there, it's still not a real form of writing.
- It wasn't made to be holy, but just to be used temporarily. Some have used this argument to permit discarding printed Divrei Torah: since they were just meant to be used short-term, they may lose their holiness afterwards. R.M.Feinstein (Ig.Moshe OC IV.39) cites the case ofhalacha that requires the burning a "Sefer Torah sheKasav min" to show that intent is necessary to make something holy. This argument is much stronger when applied to an E-reader. The person has no intent to create a lasting holy text, just to read it for a minute. Therefore, there should not be a problem to turn the page.