METHOD 1
Adobe removed the ability to create 3D PDFs after version 8. (They sold it to tetra4d).
But you can still open 3D PDFs in Acrobat.
If you can find and install the superceded Adobe Acrobat 3D Version 8 you could produce 3D PDFs.
Acrobat 3D uses information directly from the graphics card so success may be dependent on your graphics card.
The resultant 3D is pretty clunky too. Not nearly as good as a DWF 3D (which can be exported directly from Revit).
The What Revit Wants blog has a link to Adobe Acrobat 3D.
This blog also has another, more round about, way of creating a 3D PDF:
Close Revit
Download and install i-model plug-in for Revit (you will have to register)
Download and install Bentley View
Open a Revit project
Open a 3D view
In the Ribbon, go to Bentley - Publish as i-model
Open the i-model DGN in Bentley View
File - Print to PDF
Tick 'Print to 3D'
Click Printer button
Choose a place to save your file
Open the 3D PDF in Adobe Reader
Have fun navigating your Revit model inside a 3D PDF file.
METHOD 2
Purchase a 3D PDF exporter.
3DA SYSTEMS: http://www.3dasystems.com/
TETRA4D: http://www.tetra4d.com/products/plugins/3d-pdf-for-revit
BLUEBEAM: http://bluebeam.com/us/products/revu/3d-pdfs.asp
METHOD 3
Export as IFC and use Acrobat Pro to create 3D PDF.
http://bim.wikispaces.com/Revit+to+3D+Pdf+-+BIM+Functionality