I would personally like to see an endless stream of civgames, but to be honest, after civ 5 fraxis will be beating a dead cash-horse. The only coustomers will be the people on this forum who are likely to commit suicide/ go crazy without the effects of the civilization drug. They can't come up with an endless number of rule changes and graphic improvements. After civ 5 fraxis should end the civ series and find a new market. I know Civilization 35 sounds appealing, but sooner or later the game will be replaced by a more advanced competitor.
I think I'd better stop talking or the forum secret police will make me dissapear. ( Thunderfall will delete my account )