All of these different ereaders remind me of the video game console flood that was part of the video game crash during the early 80s.
"At the time of the US crash, there were numerous consoles on the market, including the Atari 2600, the Atari 5200, the Bally Astrocade, the ColecoVision, the Coleco Gemini (a 2600 clone), the Emerson Arcadia 2001, the Fairchild Channel F System II, the Magnavox Odyssey2, the Mattel Intellivision (and its just-released update with several peripherals, the Intellivision II), the Sears Tele-Games systems (which included both 2600 and Intellivision clones), the TandyvisioN (an Intellivision clone for Radio Shack), and the Vectrex.
Each one of these consoles had its own library of games, and many had large third-party libraries. Likewise, many of these same companies announced yet another generation of consoles for 1984, such as the Odyssey3, and Atari 7800.[2]"
http://en.wikipedia.org/wiki/Video_game_crash