On my very, very brief time on this forum, I have noticed that some people have theorised that there will be an Alien Invasion DLC campaign. I have also noticed that a lot of people are against the idea. Personally, I am not only all for it, but believe it is also likely.
My reasoning for this begins with all the little alien easters eggs hidden around the map, as well as the drug induced Alien Invasion nightmares that Michael has early in the game. Anyone who has seen these knows that quite a lot of detail has gone into the models for both the aliens and their spacecraft, far more than one would expect for a simple easter egg or a quick segment in a dream sequence. Therefore, I think that these are early hints to a future DLC campaign.
Now, I know a lot of you don't think that Rockstar would do something like this, because it would clash with the realistic nature of the game. I, however, would not put it pass them, for the simple reason that they have done something like this not to long ago. I am, of course, referring to the Undead Nightmare DLC campaign for Red Dead Redemption. In that bit of DLC, we saw a full on zombie apocalypse added to an otherwise realistic, gritty western, so it would not be out of the question for them to add a full on alien invasion to their realistic, modern crime drama.
Now, if you don't think that Rockstar should produce an Alien Invasion DLC campaign, that's fine, you're entitled to you're own opinion. I am simply giving my perspective on this issue.
If you do feel like giving a counter viewpoint, please keep it civil, I am not trying to start an arguement, just a rational discussion.