...not in the M&A sense (mergers and acquisitions) but in the API sense.
SketchUp now acts as a front-end for ArchiCAD. The idea is to do 3D sketching in Sketchup, and then import the sketches into ArchiCAD for detailed design and output of drawings. The automatic data transfer translates Sketchup objects into ArchiCAD objects on a generalized basis:
horizontal surfaces --> slabs
vertical surfaces --> walls
oblique surfaces --> roofs
components --> objects, doors, or windows
If the generalized xlation ain't good enuf, then you can define rules to specify which SketchUp elements are converted into ArchiCAD construction elements. To transfer a multi-story SketchUp, however, you need to manually slice it at the appropriate heights for ArchiCAD to translate it into stories.
SketchUp users who also use ArchiCAD can download the free add-on here, after registration.