Tomorrow, Facebook will reveal to the press what it’s been “building.” What could it be? Zuck rarely invites us to his corporate home, so it must be special—and here are our best guesses.

The invitation itself is light on clues—Zuck & Co. need to take some pointers from the Cupertino Crew—so trying to decipher it like Apple invite-style hieroglyphics probably won’t yield much. But the claim that Facebook has been building something suggests this is more than just another feature update or app refresh—in all likelihood, it’s an entirely new thing. At least we hope. Or I am on a plane to San Francisco for nothing.

So what might Facebook be building? A hovercraft? New emoticons? Or maybe this stuff:

Facebook Search

Mark Zuckerberg wants Facebook to be the Internet, not just a big part of it. And you sure as hell can’t conquer the web without search, an area where Facebook happens to be pretty deficient right now. Trying to search for anything other than your friends is a chore, frustrating to the point of trivial. But think of the potential: searching for music that’s annotated with the music picks of your friends. Looking up local sushi for a business lunch with results that incorporate your coworkers’ reviews. And so forth. Google’s tried “social search,” and it’s ended up pretty terribly, because nobody uses its social network. But everyone you care about is already plugged (and deeply invested) into Facebook.

And it doesn’t even have to be better than Google. If Facebook can offer us a pretty good way to search the web without leaving our social HQ, a lot of us will use it just because it’s there and it’s convenient. After all, Facebook Chat helped murder AIM, and Facebook Chat is garbage.

A Facebook Phone (For real, this time, seriously guys)

The Facebook phone is one of tech’s great white whales, but Zuck might just be crazy enough to try it in 2013. He gave a half-denial back in September, saying it “didn’t make sense,” but what didn’t make sense in September might make sense in January. Or maybe it’s still a bad idea, and they’re going to give it a go anyway. Or maybe he was lying. Sometimes execs do that.

But what would a Facebook Phone mean? Most likely, the company would go the Kindle Fire route and make a version of Android that barely looks or feels anything like Android for someone else’s hardware, centered around Facebook features—your friends are your default address book, Instagram is your camera app, FB Chat is your default IM client, FB messages are your default email service, and so on. Although this would mean Facebook staking its mobile future on a competitor’s technology, so maybe Zuck will pull a heroic move and pull WebOS out of its cold grave. The beloved-and-abandoned software is open source now, and ripe for the revamping—maybe Facebook can spin it into something people will actually, you know, buy. The underlying tech is certainly there, and solid. But does anyone really need this? Or even want it? The Facebook app across all platforms does it job pretty damn well, to the point of making a phone based entirely around it questionable. Why buy something new when your current thing already does it well?

Still, it’s by no means out of the question—Facebook is under invisible pressures to sell us a phone just like Apple was under invisible pressures to sell us an iPad. Money makes companies do things, not ideals. And hell, if Android users are willing to go all in with Google services, there’s no reason to think Facebook’s zealots couldn’t be persuaded to do the exact same thing.

Super Chat

Facebook and Skype teamed up two years ago, and then… nothing interesting happened. Sure, FB does rudimentary video chats that never work very well, but the whole thing is pretty meagre, given how powerful (and popular) Skype is around the world.

So it’s only natural that Facebook would go further with both voice and video, turning your browser into a telecom hub that skirts your phone entirely. Imagine this: Google Hangout-style group videochats (probably the only enjoyable part of Plus) plus free VOIP calls to landlines and cell phones (already teased with FB’s latest app update). This wouldn’t just be a boon for Facebook’s one billion users, it’d be a big blow to Facebook’s competitors. Like search, a video and voice superchat would be something that draws us away from things that aren’t Facebook, and into the blue and white maw—and hey, now you’re looking at more Facebook ads.

New News Feed

The way we learn what all of our friends and exes are doing with their lives has looked more or less the same since 2006. But Facebook has become massively more complicated over the past half-decade, and the misalignment shows: your feed is getting pretty awkward to navigate. You’ve got friends, close friends, acquaintances, recent posts, tweets, “top stories,” photos, videos, Spotify playlists, statuses, wall-to-walls, and a scattershot of other life fragments. There’s no easy way to sort it, and there are plenty of easy ways to get lost in it. And just wait until everything everyone watches on Netflix gets dumped into the mix.

In the era of linked accounts and 2,000 friend online social groups, Facebook needs to build a simplified, streamlined way of seeing what the people you care about are doing, and just piling on new features to the same stream we’ve had since the Bush Administration is only making things worse. The brain can only comprehend so much. A news feed that’s as radically redesigned as Timeline was for the profile will curb the sensory overload, and maybe actually give you insight into your buddies once more.

So, maybe they’ll do that. Maybe they won’t. We don’t know.

But we will know exactly what Facebook is building tomorrow, when we post live from Zuckerberg’s lair at 1 PM Eastern Time. Maybe I’ll give you a call from my Facebook phone.