As all good Back to the Future fans know, this year — 2015 — is the year that Marty McFly and Doc Brown (and Jennifer Parker) traveled thirty years into "the future." This was in the movie Back to the Future, Part II, which released in 1989. It's undoubtedly the weakest film in the trilogy, but that's a topic for another day.

The official Back to the Future Facebook page posted something mysterious today. It's a large promotional image accompanied by no text other than the hashtag "#BTTF2015." See for yourself.

The original Facebook post can be found here.

What could it mean? It has to be in honor of the year (2015) and its significance to Back to the Future. But what is Universal Pictures planning, exactly? Let's take a quick look at the possibilities:

1. Big-screen re-releases.

Maybe Universal is planning to do the Jurassic Park 3D thing, doing a 3D conversion on Back to the Future and releasing it for a limited run in theaters. There could be worse things than seeing the classic scifi/comedy on the big screen again, with high-quality 3D visuals.

2. New home video Special Editions.

In the tradition of Star Wars, perhaps Universal is planning to release new editions of the trilogy on Blu-ray or digital or something else (4k?). "Special Edition" can mean a few different things, such as "loaded with extras," behind-the-scenes footage, etc. Or like Lord of the Rings, there could be footage that was cut out of the original films added back in. This would carry a label of something like "10 minutes of never-before-seen footage!" or some such.

At the very bottom of the poster, are the words "Universal Studios Home Entertainment," which all but guarantees this teaser is related to the home video versions of the films. But that doesn't mean it's definitely the movies themselves...

3. New BTTF merch.

Remember all that cool stuff Marty saw in 2015? The self-drying, self-tailoring jacket. The auto-lacing sneakers. Flying cars. Mr. Fusion. And who can forget the iconic Hoverboard? Maybe there's a new product (or products) launching this year that brings to life the item(s) used by citizens of BTTF's version of 2015.

4. A new theme park attraction.

A new Universal Studios ride or attraction could be in the offing. What better way to celebrate Back to the Future II's "future" than by bringing it to life in sunny Orlando?

Those are our theories. Got any to add?

We'll keep you posted as Universal releases more information.