I love Star Wars, so naturally, at the moment, the one thing that just makes my day is watching the trailer. 3 or 4 times over, keeping it small.
During my many watchings of this trailer (after about the 5th time in a row), a pretty amazing/cool thing happened (and this is where I state the obvious), like the title of the movie suggests, The Force AWAKENS, everything we see in the trailer is AWAKENING. *I'm not sure if my following theory has been discussed yet, so be nice*
Bear with me now, this is where it gets cool; all the characters we see are in some form of hurry, or seem to be under incredible stress. So what if, per say, all the characters we see ARE force sensitive...
... And are being hunted by the remaining Empire's forces?
Wouldn't something as big as this then push them all together, somehow?
For example, John Boyega's character appears to be running from something/someone, maybe because he has discovered he's force sensitive, (and apparently we hear a probe droid as background noise), and he's crash landed on Daisy Ridley's planet? Through the Force, they would eventually find each other, right? Seems a logical assumption.
Daisy Ridley's character also appears to be running from something, and seems panicked. Her little droid also seems pretty agitated.
The Rebellion, as we see from the X-Wings, is clearly still active, so maybe Oscar Isaac's character, being Force sensitive as well, would be tracking down the Force sensitive people and protecting them, or introducing them into the rebellion, to give the Rebellion an advantage against the Empire.
If all this is assumed correct, the Sith villain would then be easy to introduce: either as working for the Empire to help track down the Force Sensitive people (whilst also collecting artifacts, if that part is true as well), or he could also be introduced as someone Oscar Isaac's character found, but then it turns he's not so nice, and kills a few of the Rebellion's pilots, and is basically neutral, needs an apprentice, and wants "absolute power" (to quote The Emperor). He could then gain this power by joining the Empire.
This would also be a logical assumption to why see a platoon of Stormtroopers exiting a landing craft on planet that could potentially Tatooine, which resembles the planet that BOTH John Boyega's character and Daisy Ridley's character appear to be on.
Now, after having typed this all up, in the most logical way possible to my insane amount of excitement after this, which could have confused all this a little bit, the question is...
Does this seem like a reliable theory to you?
*Sorry about the massive last image*
I personally, would love it if this was the situation in the movie. It would be like a continuation of Order 66, so, at some point, there could be an Imperial Officer from the Empire, telling them how Order 66 was never fully carried out, and how Force sensitive people always pop up, and that it is impossible to predict where, but they have to keep them away from each other, or get them to join the dark side, through the Sith we see in the trailer.
Also, this could also potentially be what the stand alone movies would be about - Order 66, one movie from the perspective of a Jedi, the other, from the perspective of an Imperial Office. I like that idea.
So anyway, that's my theory.