According to their official podcast, we have basis to believe the announcement will somehow involve the new Leerdammer update.
Discussing the possibility of improved user profiles, an LBP staffer confirmed that such an update was "imminent" and a part of the latest "Leerdammer" update. Apparently the functionality is "cooler than anything" the user base have asked for, so hopefully we'll get some really mental, detailed profiles.
In addition to that, the team discussed the length of time it takes to create a Media Molecule level and clarified that there is a full 10 weeks involved in getting an "official" level finished. However, despite the long level building process, the team did conclude that new levels are on the way along with a music-only pack. The music-only pack will include a few new tracks for use in levels, a welcome addition if you ask us.
The LBP staffers did discuss their long term hope of providing tools to allow people to create their own music, something that would be right up our alley to be honest.
With so much planned for LittleBigPlanet in the future, we wonder how long it will be before Sony start bundling the game with PS3s. A win-win-win for all involved really. Sony get to make the PS3 more consumer attractive by bundling a great game. Media Molecule significantly increase the fanbase to which they can market premium DLC (which appears to be their business model for the game). Consumers get a great, great game with their PS3.
It seems like a no-brainer to us.