Ok, not sure how I missed this one for ICS features, but the native SIP support in ICS is GREAT! Configured up an extension on my Asterisk box, forwarded some of the ports across on my firewall (remapped them to avoid voip hackers) and reconfigured Asterisk to accept external extensions, and it works
I can both make and receive calls SIP with the Nexus. VERY cool...
-Mike

-Mike