I've converted my ardunio to ethernet using a module from wiznet, found here. It is working great
I did find some software to create a virtual serial port to a specific ip, but they wanted some big bucks for it. I still have hope that it can be done. My next step was going to sniff the com port during an upload and create my own program to send the same thing over tcp to the wiznet.
...set upload.verbose to true in the Arduino preferences file. Then avrdude will dump every byte that goes by.