We have been working on this one for the last couple of weeks. There is now a WDM to KMDF porting guide on WHDC. There are 2 documents in the download. The first is a very in depth document which goes into great detail about each function, IRP major code, etc that you need to port over. The second is a set of tables that will help you with the porting. This second document is much shorter then the first. The tables map from KMDF function groupings to WDM concepts and also try to map in the other direction, from WDM to KMDF.
Please let me know if the docs are useful or if you find anything confusing.