When people try to make a sequel to a game, very often it is because some company wants to repeat the exact same success the original had. This is what causes them to turn out unoriginal crap because they have no interest in producing something original, all they want is the profit from the original and more, like EA. But I would doubt that would happen with GF considering the success of the first one, so who ever would try to make a sequel of it would be very likely doing it out of a labor of love.
In fact, I'd be happy to hear if Tim is not behind the sequel. I respect his wish to keep working on original stuff (a mentality completely opposite to LucasArts), plus it would be interesting to see a different person's take on the verse, so long as the for-profit mentality is not solely backing their interest. This happened with Homeworld where a different studio made what was at first considered a non canon sequel to the game, but turned out to be really fun for fans with such an interesting story that the fan base made it canon. Instead the original studio's "real" sequel turned out to be a rushed game with just better graphics, but had no soul like the previous two.
The only thing I could imagine that would most annoy me in a sequel is if they made it faaar too cartoony. That's what was amazing about GF, that it kept this amazing balance between cartoony and noir such that it was silly enough to enjoy the comedy but serious enough to enjoy the drama.
However I'm not really worried about this. The game is so removed in time and has grown to such a mythical status that I don't think it's possible to tarnish it, and if someone managed to it wouldn't be as bad as this
. So I don't see a reason why someone shouldn't take a risk in try to do a sequel.