That is true witrh the whole image burning thing. Happens to LCD TVs too if a game is paused for a while, it could easily burn the image into the screen itself. But....still not stopping me from getting a PS Vita, I still want one, so yeah XD
I might not play it so much as outdoors really though, I'd probabally just want to play it in my room, or if I have a job, on my breaks at my job or whichever. Playing outside would be tough for me as if I'm concentrating on the Vita while walking, I may not see where I'm going ot anything like that. But it's still good to know regardless.