One problem with that is games and emulators that write directly to framebuffer won't be captured by apps like gtk-recordMyDesktop, istanbul, xvidcap etc.
Though maybe someone with more of a clue could refute my assertion.
Since the Pandora does not have a lot of processing power, screenrecording isnt really a very viable option. The better option is to get a video out cable and record the screen externally
MHL (as I understand it) comes from the manufacturer adding addictional pins inside the micro-usb port. Since the pandora was not manufactured with this, it can't be done.