"Virtual routers" from Cisco

Fellow NANOGers, A friend of mine told me about a new "breed" of routers from Cisco which have two "virtual machines" over the same physical hardware -- sort of a VMWare or Xen host with guests. Does someone know about that, or had a practical experience with that new Cisco product? Abraços, Marlon Borba, CISSP. -- Virtual é legal: Virtual PC, VMWare, Xen! --