Microsoft and VeriSign have own flavor of how to protect networks from infected computers: This new architecture will be based on Microsoft's Network Access Protection (NAP) and VeriSign's Unified Authentication platforms. It's supposed to protect networks by checking that a laptop trying to connect over Wi-Fi has been issued a clean bill of health with the latest patches and virus definitions, among other factors.
But this announcement doesn't mention a press release from yesterday from the Trusted Computing Group's Trusted Network Connect specification will also work with NAP. The TNC spec allows computers that connect to a network through any medium to validated for security before being allowed access. It ties nicely into 802.1X port-based authentication. If a computer fails validation, it's segregated on a protected VLAN that only offers access to patches and updates, but can't reach the rest of the network.