Renesys' always excellent coverage throws some more light. They say the routers are all still up, there haven't been any routes withdrawn, but packets are just stopping somewhere on the way into libya. Firewalled I'm guessing, so privileged parties can still communicate.
http://www.renesys.com/blog/2011/02/libyan-disconnect-1.shtm...
http://www.renesys.com/blog/assets_c/2011/03/latencies_Libya...
The second one is a plot of traceroutes into libya over 24 hours.