We used to run routing on commodity computers - then came hardware routers because you could do things faster when you specialized. Now we are back to writing new software routers to run on commodity hardware because hardware is now fast enough. Is that right? Looks like http://blog.gardeviance.org/2012/03/tens-graphs-on-organisat...
Sort of but not really... openflow keeps the specialized network hardware, in the form of switching fabrics etc, but allows for a common set of programming instructions to be applied, so routing decisions can be made based on simple rules in the hardware, or exported to a computer to decide routing (for the packet or flow) without needing the computer itself to process all the traffic. This is different than using a computer with N ethernet cards, where all the data had to be marshalled around.
Except Google isn't using software routing. The data plane is still in hardware; they've just replaced crufty distributed control plane software (IOS/JunOS) running on a slow embedded processor with Googly centralized control plane software running on x86 servers.
