The studio said this week: "Parts of our team have also been in pre-production on our next major project, and that game is at the point where it requires the studio's full attention to make it our biggest and best work yet."
While it's not yet known what the studio's working on, early speculation points to it being the next entry in the Fallout series. However, Bethesda's Pete Hines responded to suggestions that the tease was for Fallout by saying "guess again".
@aegies You talking about the Vine thing? Guess again :-)— Pete Hines (@DCDeacon) April 16, 2013
The trailer shows a spinning record, which may be Air on the G String, the first recorded work by German composer Johann Sebastian Bach. NeoGAF members point out that a number of Bach's works featured in Fallout 3.