And as I suspected/heard/feared, the piano parts for Mary Poppins have a lot of notes. A LOT. The Key 1 book really is like a concerto, and the Key 2 book has it's share of exposed solos too.
What's really cool is that they are using pianos with built-in MIDI triggers - or something like that. I forget what their proper name is. Basically, we're playing on a real piano: Key 1 is a grand piano, Key 2 is a full upright. However, there's a lever that mutes the "live" piano action, but still allows the piano keyboard to be played, but instead of the strings sounding, the hammers triggers MIDI controllers, a.k.a. other sounds. So, the piano can end up "sounding" like a theremin, a celeste, a harp, etc. And it can also be set-up to play the "live" piano and a MIDI generated sound at the same time. Wicked and Curtains use the same set-up, however, I believe Mary Poppins is the only one with a grand piano in the pit.
In short, I have some practicing to do over the next couple of weeks. But it will be nice playing on a real, weighted action, piano keyboard.