To quote Sheldon Plankton: I WOULD!!!
And in case you didn't know, Seth Green himself is a brony! Just look at this pic:
Proof that Seth Green, star of Family Guy and creator of Robot Chicken, is a Brony!
I'm sure they could find some action figures /dolls somewhere of the characters that they can use. It would be so awesome! Just think of what they could do!
I'm thinking about maybe starting a petition for people who want to see such a sketch (or hopefully series of sketches, as I can't imagine they would get those figures for a single sketch).