I appreciate this and the previous comments, but I gotta say: this sounds like a lot of schlep.

I may be wrong, but I feel like the right persistent chat service can/should become a 21st century usenet/google group, where the conversation is always happening, IFFT-style hooks help you filter/act on info, and history is Gmail-simple.

I'm investigating a group-chat solution right now for an organization of several thousand non-technical members, and my intuition tells me IRC would simply not be adopted by most users.