It's been just four months since Spotify — a popular digital music service that lets users stream any of its 15 million songs — launched in the U.S., and already the company is headed in a "new direction." The details of the mysterious change will be announced at a press event next Wednesday, Nov. 30. In the meantime, techies can't help but speculate. What might Spotify announce? Here, four theories:

1. A Spotify music store
My money's on a "Spotify mp3 store launching in the near future, with plenty of integration with Facebook," says Tom Cheredar at VentureBeat. That would put Spotify in direct competition with iTunes and Google's recently announced music store. Yeah, says Peter Kafka at All Things D. An mp3 store seems likely given that Spotify already offers one in Europe.

2. A slew of new Spotify apps
I "respectfully disagree" with the mp3 store theory, says Eliot Van Buskirk at Wired. Instead, I think "Spotify will announce a commercial API (application programming interface) that lets app developers for iOS, Android, and other platforms build — and sell — music apps that draw on Spotify's catalog of 15-million-plus songs." Imagine a bounty of apps boasting a "wide range of features for playing back and sharing Spotify's music." That would let Spotify "flex its muscles a bit to show bands, labels, and publishers that if they're not on Spotify, they won't be part of this ecosystem."

3. A new video venture
"Spotify might be planning to launch a video streaming service to rival the music video traffic currently being lapped up by YouTube," says Adam Bunker at Electricpig. There were also rumors earlier this year that Spotify was talking with film studios "about a possible deal for distributing feature films," says The Local.

4. Any number of new features
"Will playlists finally be searchable from within the app? Is the player finally getting the social features it so sorely needs?" asks Thomas Houston at The Verge. Maybe there's an iPad app in the works. "Whatever the news, we'll be there next Wednesday."