If nothing else, Contiki proves that "it can be done." A related project, lwIP, sounds like a good candidate for a small, open, and free IP stack packaged as a bsdsocket.library replacement. (Queue the naysayers.) Actually, the Amiga stands to benefit from all of Adam Dunkels' projects, assuming there are one or two dedicated programmers willing to put in a few hours of their spare time.
Trev