Bah!!.. that's the worst idea i've ever heard. Meryl, was a wreckless cry baby in MGS...if she wasn't in the game Mei Ling or Nastasha would have been the main female protagonist.IMO
Also if Meryl wasn't in MGS, Snake wouldn't have had to run all the way back to the Armory to grab a sniper rifle and save her..that was very time consuming and not necessary.
At best she deserves maybe a little cameo in MGS3 maybe a codec conversation...ok,ok, maybe a little sidequest or something but to play as Meryl would be really lame..unless they change her whole persona..ya know make her less of a crybaby and more of a babe like Mei Ling or Nastasha.
.. lol!!