I was at the AIA Large Firm Rountable CIO meeting this pasgt week in NYC and one of the discussions was the problem with the AutoCAD 2007 file format and the problems that it has created for WAN Acceleration tools like Riverbeds. I am not going to try to get into all the technical details, but apparently the AutoCAD 2007 file format uses a new compression scheme that basically reorganizes the file each time you save. Because of this WAN Accelerators are not able to identify patterns in the file as well and WAN Acceleration is severely impacted.
Autodesk and Riverbed are aware of the problem, but Autodesk has not provided a fix at this time. It was suggested at the meeting that if Autodesk could provide an option in the next release (2010 - as 2009 products are in beta) that would allow the user to disable the new compression, this would resolve the problem.
This is an issue on all the AutoCAD based applications, such as AutoCAD Architecture, AutoCAD MEP, etc.