Blogland is big. I am currently trying to get a bit of an overview what people out in blogland are doing with WCF. And while I've been doing that in addition to a bunch of very long and (due to the time difference between Redmond and Germany) very late evening meetings, Sabine has caught the Sudoku virus and keeps filling those grids ...
It turns out, there is convergence between WCF and Sudoku. ;-)
I have seen a few people pointing it out already, but in case you haven't seen Kumar Gaurav Khanna's WS-Sudoku (blog post) game, you might want to take a look. It's ClickOnce installable (given you have the WinFX Feb CTP) and lets a group of people solve a puzzle together. Very nice demo.