In case you hadn’t heard, iCloud is coming. No one knows what it is yet, but because it’s Apple—and because it’s cloud—it is expected to be huge.

So huge, in fact, that Apple actually put out a press release on it. No, wait—the release is actually about CEO Steve Jobs keynote at the company’s Worldwide Developers Conference on June 6 and barely mentions iCloud, stating only that Jobs will address “unveil … iCloud, Apple’s upcoming cloud services offering.” That’s at the end of a list of other things Jobs & Co. will unveil, including Lion, the next release of it Mac OS; and iOS 5, the latest software for the iPhone, iPad and iTouch.

But this is the cloud, people. Of course it’s most important. Why else would there be more than 1000 results (and rising steadily) in Google News for the term “iCloud” at the time this story was written (soon to be plus one, once this story piles on). All that for something we know next to nothing about, and won’t until next week. To be fair, though, Apple did (allegedly) pay $4.5 million for the domain name iCloud.com—so I guess it is safe to say it’s significant, and worth spilling some early virtual ink over.

Since we don’t really know what it’s all about, here, then, is a brief roundup of some of the more interesting speculation out there about what iCloud holds in store:

  • A story on sister site ConnectedPlanet.com even speculates that iCloud may not have a cloud component at all. Read the story to understand why.

  • CNET is speculating that iCloud could stream movies and TV shows in addition to the widely speculated music.

  • Wired thinks iCloud will be a new online media service offering that replaces the “embarrassingly flawed” MobileMe.

  • Time predicts that iCloud will be an online repository for documents created in iWork, allowing users to sync seamlessly in the … well, cloud.

I’m going to hedge lamely, and say this: Those are all good guesses, and I predict that iCloud could be a combination of any of those components. And maybe more. But no matter what, it’s going to be big. It’s Apple, remember?