Since Dave Ward's presentation on Software Defined Networks at Nanog there's been a lot more of it about. SDN feels a lot like MPLS (Multi-protocol label switching) did when it was first introduced - it appears to simplify the operation of the network without actually doing so, and it gives the industry a 'big new thing' to talk about and compete over.

Ivan Pepelnjak thinks so too - he's enthusiastic. So is James Hamilton (Amazon).

Links

James Hamilton - http://perspectives.mvdirona.com/2011/10/23/SoftwareDefineNetworkingCom