Might have been one of the periods I was busy as I didn't know about that port. Good work dinau. There is a couple of things I'm not a fan of, not something you could do when directly porting, but something I feel is needed to be fixed in the future. Mainly making it easier to pick between W5100 and W5200, and allowing different SPI ports to be included. The main purpose of these changes is to allow more control within the IDE.
I also noted that a few example sketches is asking for String class. This is something I'll try to follow up.