Here is a thread exploring the capacities of Cycles (in spanish): http://www.foro3d.com/f114/reto-aprender-cycles-98141.html

It is in spanish, but the screenshots are very self-explaining. This thread is alive, then there will be more advances.

P.S. And I talked about cycles a time ago
http://moi3d.com/forum/index.php?webtag=MOI&msg=4256.1

:-)