What are virtual routers and how can they lead to virtual data centers?

OK, you’re a CIO and when you go down to the data center, you see racks of routers, each with a maze of cabling. When you hear “virtual routers” you think of all of that gone, replaced by mystical router instances floating about somewhere in the ether, and you smile. Or you’re a CFO who gets a bill for hundreds of branch routers, each picking your pocket on service charges and maybe software licenses. You hear “virtual routers” and think of all those little hands going out of your pocket, and you smile.