Not too long after the release of Broken Sword: The Sleeping Dragon, Revolution confirmed that pre-production on Beneath a Steel Sky 2 had begun. The project has been featured in our Hype-o-Meter ranking ever since.
However, Revolution also maintained that Broken Sword 4 was a possibility. According to multiple sources, it now looks like it's not just a possibility but in fact likely to happen. It seems we can no longer assume that Beneath a Steel Sky 2 is the only. or even the primary, game Revolution intends to make next.
Revolution's BASS 2 entry in the Hype-o-Meter list stays unchanged until we know more, though given the time it takes to produce a game, we may not hear anything official on the developer's plans for some time.