A bit later than planned, but I've just uploaded the first release of deSleeper. To download go to:
http://desleeper.codeplex.com/Release/ProjectReleases.aspx?ReleaseId=16344
This release, in my rather limited test environment, works as a proxy. There is more functionality planned to extend the reach and make it a bit more user-friendly (no MAC addresses, for example) which may or may/not be working. But basic proxy is working fine.
You'll want to install .NET 3.5 SP1 before using deSleeper.
Enjoy