I would love another game in this series. Not even, necessarily, A Puzzle Agent game. But ANYTHING to do with the rich character that is, Nelson Tethers. I've heard lot's of people say the humor is predictable and lame, but I kinda like that. Nelson seems like an awkward teenage loser, yet as an adult.
I wouldn't want a new game to have anything to do with the story in this one though, not that it was bad, but because I would like a fresh, new one.
The only thing I'd like, is, like someone has said already, to figure out what was in the space suit.
Anyways, I do hope for another Nelson Tethers game!