Ok people i want your imagination on this and tought's on what is going to happen in season 4,what is going to be the story line and what you think that is going to be happening into season 4?!What story plot do you want to see for Example?!

To be honest with you, I really CAN'T imagine it.

Now that I've seen the season finale, my guess is that our Olivia is gonna have recurrent dreams, or something like that; about Peter...
But really, no clue.

okay, Peter will be stuck in Observer land where all their past 'tools' have disappeared to. so this place will sort of be like limbo. he'll be able to see what's going on in the present but have no control over events. and of course he'll be very distraught that no one remembers him. eventually he'll meet some other Observer 'tool' and he'll find out where he is and what's going on.

Meanwhile in the present: Olivia et al and the alternates are fighting just as much as always because there's no mediator (like Peter). Eventually they'll start to hash stuff out. with the combined mental powers of two Walters, they are able to come up with ways to permanently fix the universes holes.

Once that happens, Peter's memory will start to form in Olivia's mind. she'll be confused at first and dismiss it as random hallucinations but eventually she'll think they're real. Once these memories become real to her she'll be able to actually make Peter materialize! so she's effectively pulling him slowly from the limbo state until he is fully formed. The Observers will be very mad at her for messing in their affairs and will come after her. they send The Mystery Guy to kill her (like they did with that other girl in S2). There will be an epic fight to the death but Olivia will be victorious. Peter will find her and take her to safety. then everything goes back to normal and they live happily ever after. (just kidding, this is Fringe we're talking about).

Furious that Olivia outwitted them, the Observers will send her to limbo. she'll be stuck there for awhile but eventually master her abilities and be able to free herself as well as several others. One of her abilities will be to hide herself and others from the Observers. Then together, they'll go on a quest to eliminate the 11 Observers so they can't get killed or sent back to limbo.

i can't think of anything else right now but i might add to this later.

I believe I read somewhere that Peter still exists, but as Walternate's son who's basically in the background. However, Olivia and our Walter retain faint memories of him.

Well what I think is that now that both universes know what might happen they're gonna work together to save both their universes and try to figure how to get the real Peter back. But I feel like Walternate and Alternate Olivia are gonna stab them in the back which will end up in their destruction and the real Peter comes back and he and Olivia are reunited. But thats just me

The thing with this show (at least to me) is that it's so hard to predict. It has so many twist and turns it is really hard to see what is coming. Even when I do manage to guess what happens while in the progress of the season, I get so shocked that it turns out right because I was only grasping at straws to begin with. I do like the ideas listed here so far though. I just hope that whatever does happen Fringe continues to grow more popular so that when it comes time to be renewed for a 5th season we don't have to play the waiting game like we have before. (And hopefully next year Emmy will show it some love and nominate it!)