Panzura has got quite a lot of press lately in the AEC market. Some really impressive numbers with synching over long distances.
Panzura's Global File System apparently goes one step further compared to caching and seems to be getting support from Citrx and VMWare.
Panzura also runs on Amazon's AWS, Aliweb I wonder if someone will step in and provide something similar for Microsoft Azure. Apparently Microsoft's DFS doesn't work very well.
Doc management system Newforma has also started looking at Panzura. Will PW also support Panzura? Or come up with something that is like GFS + hardware controllers (from Steelhead?).