I just recently found out that I have a couple of lines to these folks.
I also found out that there is a Google group "Katherine Swynford" that is very active and has alot of excellent information about current research being done in England. They actually have a "study" day in June in Lincoln about them.
There also are a couple of new books out about them besides Anya's Seton's "Katherine" which has just been re-released!
Anyone who would like to learn more about these ancestors will enjoy this group.
Who knows? If we get enough people excited, maybe we could plan a "family reunion" in Jolly Old England!