Being the hackery-type that I am, I have been poking at my newly purchased Roku HD.
It turns out there are four ports open on the Roku. 8080, 8085, 8086, and 8087. After different attempts, the only fun I could come to is that you can telnet to your Roku on port 8080. The other ports did not respond to any of my hackery. I wonder if they are service ports left open for some reason?