You would have a walk cycle for quad and byped, yes, but you would then have to animate the getting up from 4 legs to 2 legs.

I cant see it being that difficult. Why not video yur self doing it and see how u get on, its a good start to watch yurself doing it first and then try to pass that into maya and animate it.

To get up you would need to anticipation of the upward movement by dipping slightly on the front legs and then showing a launching/pushing movement. Once thats done it will be how much pressure is placed on the muscles and spine to get it into a biped stance. then away you go...