There is a great irony at the heart of the Internet. Free software and its characteristic distributed development method were made possible by the Internet. Similarly, many of the earliest free software programs - Sendmail, BIND etc. - helped create the Internet. And yet today, the knots of the Net's interconnections - the routers - are generally proprietary (and usually from Cisco).
So here's an idea: how about creating an open source router? Enter Vyatta, which is doing precisely that. It's been working on the idea for a while, and, according to GigaOM, is close to launching its first product.
Assuming they get it right, I don't see any reason why this shouldn't steadily chip away at Cisco's dominant market share, just as every other open alternative to commoditised products has done. As they do, expect other open source solutions to enter this market soon.