I've seen that players can log in even while the GM isn't logged in. This can be handy for people who may decide to play by post between regular sessions, but the chat log isn't persistent. Meaning that if Bob rolls to-hit, and damage overnight, there's nothing in the chat log when the GM logs on in the morning.
With this there should be a GM option to clear the chat log from time to time.
Edit: I see where chat archives are on the to-do list. Easy to tie this in with that... ;-)
