I think I've solved it. Pin 9 is a red herring, sort of. I never got it to blink, but I was able to get code to bootload successfully via ethernet.
The very last piece of the puzzle: windows firewall was blocking tftp. Added an exception for that and it works now!
The EtherTen combines an Uno-equivalent Arduino-compatible board and Wiznet-based Ethernet support, along with a microSD card slot and Power-over-Ethernet support. [Product page]