From Geometry Gym downloads page:
Geometry Gym IFC text tree viewer, Unblock zip (right click Properties) and then unzip into a folder of your choice.

ggIFCTreeViewer.zip (4th February 2014) 
via https://twitter.com/owensharp/status/430502199429300224

EDIT Updated link as of 26 March 2014
http://geometrygym.wdfiles.com/local–files/downloads/ggIFCTreeViewer.zip

You can also view the embedded coordinate information in the IFC, for example:

Geometry Gym has released an IFC importer for Vasari Beta – links below:

ggRevitIFC2013x64 v0.0.37.msi (13th September 2012) REVIT 2013

ggRevitIFC2012x64 v0.0.37.msi (13th September 2012) REVIT 2012

ggVasariIFC v0.1.0.msi (18th September 2012) VASARI

64 Bit Vasari, Revit 2012 and Revit 2013 Addon to import IFC files.
Addon undergoing rapid development. Please use with care and send suggestions and observations.

via
Downloads – Geometry Gym

Image from Geometry Gym

Heads-up:
Geometry Gym: IFC Importer for VASARI

A lot of you may have heard about it already, but if you haven’t:
Chameleon is a plugin for both Grasshopper and Revit with a focus on interoperability, simulation, and efficient practice workflows. Chameleon’s main advantage is its ability to facilitate easy transfer of geometric data between Grasshopper and Autodesk Revit, but also includes other valuable tools to make life easier, both in Grasshopper and Revit.

This latest version includes upgraded the functionality of the Curtain Grid management tools for Revit users. These tools now allow control of curtain panels in addition to the grids and mullions. There is also a preview to show the results of changes before accepting.
via
CHAMELEON � HIROSHI JACOBS

Heads-up / read more:
http://www.formfollowsperformance.com/2012/07/chameleon-grasshopper-revit-geometry-transfer-and-edit-params/

Steve’s post:
http://revitoped.blogspot.com.au/2012/07/chameleon-for-grasshopper-and-revit.html?spref=bl

More Grasshopper resources:
Perkins+Will Grasshopper Users Group

On a slightly unrelated note:
Video showing point based parametric functionality from Grasshopper to Revit Adaptive component (more about Geometry Gym here):

importing IFC2x4.  Thanks to Geometry Gym, and Jon Mirtschin in particular, an IFC importer add-on for Revit 2012 is under development that aims to support IFC2x4 with nurbs profile / perimeter exchange.

Jon says:
I’m developing the Revit addon to import these files as the functionality is not available in the native importers. I haven’t built for Revit 2013 yet, but if you have Revit 2012 and want to try, the installer is available from http://www.geometrygym.com/downloads
via the comments at:
Geometry Gym: NURBS GH to Revit

And here is the link to the current build of the IFC 2×4 importer for Revit 2012:
ggRevitIFCx64 v0.0.11.msi (24th April 2012)
Note, Revit 2012 64 bit Addon to import IFC files.
This is an early public release for initial feedback and comment. Addon undergoing rapid development. Please use with care and send suggestions and observations.

(from http://ssi.wikidot.com/downloads)

Image from Geometry Gym

Here is an excerpt showing how IFC2X4 RC2 improves geometry capability:

Geometry
Additional entities are added to the geometry resources. (1) The definition of manifold boundary representation has been enhanced to include advanced B-reps, based on NURBS. Therefore b-spline surfaces and b-spline curves are added. (2) The curve bounded surface based on bounding p-curves (curves defined in the parametric space of a surface) is added to allow any surface to be bound; it was restricted to only planar surfaces before. (3) Tapered solid of extrusion and tapered solid of revolution are now included to define simple taper, restricted to one section and to topological similarity of the start and end profile. (4) A fixed reference swept area solid is added to define an advance sweep along a directrix with a fixed orientation of the profile. The swept disk solid has been simplified by implicit start and end points on the directrix. (5) Elementary surfaces have been enhanced by incorporation or cylindrical surfaces. 

From http://buildingsmart-tech.org/ifc/IFC2x4/rc2/html/annex/annex-e/IFC2x4-RC2_whats-new.htm