WMI filed the FDIC claim because it was a procedural prerequisite to filing the lawsuit. It's that simple.
WMI's deadline to file a suit rapidly approaches and a suit will be filed. Once it is filed the defendants can try to delay discovery, but if they really need to avoid exposure of some something they will settle. Indeed, I believe the groundwork for obtaining settlement funds was laid two days ago when Bair, Bernanke, and Geithner started their campaign in the Senate for the $500 billion credit line.
Finally, you have seen nothing that I have not seen and my experience leads me to a very different conclusion. Even a junior bankruptcy lawyer at a quality firm would tell you that a suit from WMI is imminent, and further that the facts and governing law indicate victory for WMI.