Sometime back it was stated by the Rayman Legends lead game designer Emile Morel that a “good portion” of Rayman Legends sees you playing as Murphy while you help guide an AI controlled Rayman. That was some upsetting news for people who wanted more of a platforming experience.
Now in the latest issue of Nintendo Power it is stated that a good majority of Rayman Legends is played as Rayman or other various characters instead of Murphy. That may be more comforting to hear, but there will still be Murphy based levels, so I guess we have to wait until the game releases and see how many levels are based off of Murphy.