Yeah, I kind of want him to keep most of his focus on the Simpsons, but at the same time, I loved Futurama and the Simpsons was still doing fine when that was going on, so I don't really think the show was negatively affected by it.
It's probably hard to start new projects after doing the Simpsons though. Since it's such a classic and long-running show everyone will probably always compare everything else he does to the Simpsons.