DNS problems

A few (perhaps 2%) of the domains I've looked up today aren't
resolving. It appears that several hosting companies have turned off their
nameservers until after this Y19100 foolishness is over. cihost.com is one
of them. I wonder if their customer SLA covers this. It seems that this
reaction is a lot like what many predict will happen to phone systems: the
date rollover doesn't break things, panic does. Has anyone on the list shut
down any equipment as preventative maintenence, and if so, how have your
customers reacted?