Here's some recent precedent. Yes, I know this is not a perfect comparison, but it's a damn good success story in a very short time frame. BitShares community, it can be done!
http://news.yahoo.com/startup-challenges-dominance-big-banks-derivatives-markets-052007280.html (http://news.yahoo.com/startup-challenges-dominance-big-banks-derivatives-markets-052007280.html)