Username or EmailPassword
I am probably somehow dysfunctional or something but I have absolutely no use for such devices. I carry a mobile phone with me all the time anyways and a mobile phone does all the things one these does while also including the ability to send and receive SMS messages and phone calls. Ie. it's basically just better to buy a phone that can do both tasks than shell out money for two devices where the functionality overlaps.
With ever more powerful mobile phones and even plain feature phones nowadays starting to sport really good multimedia features and big screen the need for separate media player devices is only bound to diminish over time. Manufacturers need to think of something new that would set these devices over the competition from mobile phone market in order to keep their place in the overall market, innovate a bit more. It remains to be seen if they can do that or will competition from mobile phones with multimedia capabilities continue to push them out.