First of all chek if /usr/portage is mounted, then
with the following command:
emerge -uDpv world (to see what will be updated)
emerge -uD world (to update)
etc-update (to update/merge the config files)
it would be good to place a note in irc when you do this so others can see and updates won't run together as this would interrupt the update started later due to lockfiles on the current updating packages.