I am doing some proof of concept in our test lab for OSD in ConfigMgr 2007. Everything else works fine. There are no speed issues on the network. Other file transfers during WinPE have no issues. However, the capture sequence takes 3+ hours for a 3GB image.
I've tried to capture using network shares on two different servers with the same results. Despite what the log suggests, I suspect there's a feature or configuration issue on the DP that the sequence is looking for but not finding. If you watch the network activity, it's long periods of nothing followed by a short burst of slow transfer. Eventually the .wim is created and I can deploy the image with no problems.
The build and capture runs on an ESXi 5 VM. I'm going to try a build and capture on a physical server to eliminate some odd driver issue, but that seems unlikely since those same drivers don't have a problem transferring files in a non capture TS.