I did an initial run of Lucene 3.0.2 through Sharpen. It stops when there is an error or finds something it doesn't have a mapping for. I added some placeholder mappings so it would at least get through a few files.
Here is a package of what I have so far: http://convid.com/alex/lucene/Lucene.Net.Sharpen20101104.zip It contains the C# files from the test run, the jars for Sharpen, and my Ant script with the custom mappings. I encourage others to look at the code and try sharpen. You can use my script to get started. Alex