Ladies and gentlemen, Revit Structure (RS) is out of the gate. Here's some answers to FAQs:

What's different about RS and Revit Building (RB)?
RS is the same application underneath, but presents the user with different features enabled and a different toolset.

Revit Structure: what's the deal?
RS provides modeling and detailing of structure such as structural engineers require. RS works with steel, wood, concrete, etc... it's not limited to any particular form of construction, though it is aimed at the building industry (more so than civil work). Current modeling apps in the field are a chore to model with, and detailing is often done in another app. Revit combines the modeling and detailing in one app. RS provides more connection possibilities than RB, with more detailing in beam connections.

RS will export 3D linework and planes used by analysis platforms for seismic loading and other forms of analysis.

RS won't at this time be used for fabrication detailing (shop drawings), though IFC linking may tighten a connection of some kind in the future.

RS and RB 8.1 users will be able to incorporate and dynamically link shared objects between them through the Coordination Monitor, which will keep track of any shared columns, walls, grids, slabs, etc. so that if one discipline makes a change, the other will be notified once they get a new version of the other's file. Changes can be accepted, rejected, etc. as needed. This means that objects need only be drawn once, and then copied/hotlinked into the other file.

An architect who starts a project hands over their central file to the engineer, who links in the arch central file, then copies elements into their own file. Revit remembers which objects were copied in from the linked file and Coordintion Monitor keeps an eye on them from then on. Then the eng sends back his central file to arch, and the back-and-forth process continues.

It looks brilliant... stay tuned!