What im about to say is quite contraversial to you people, but give it a listen.
what if you made a super fabulous game and everyone loved it. then you spent ages and ages thinking of ways to gain popularity for the next one.
if someone said you could tell the fans that there could be no more of the next one, wouldnt that cause an uproar, many forums with many questions, more talk on the next game, people lookin for pics, rumours ANYTHING! and then one day you say hey people we are so kind and are gonna make another one for you people. then all the fans think yay i dont care when its coming out as long as its comin out.
im not sayin its true, just thats its a possibility that AM2 were already thinking about makin another one of the most popular games.
think about half life 2