Facebook has just turned on Chat in a “few networks” (including mine) this morning and I think it’s a great implementation. While Facebook hasn’t announced an official rollout schedule, Chat will be gradually rolling out over the coming days.
You can then minimize the chat window to get it out of the way. If you close a chat window accidentally, you can view recent chat history by opening a chat window with that same friend. Although recent chats are saved across sessions, older chat conversations are NOT archived. You can click “clear chat history” to clear the chat window immediately at any time.
For a few developers like social.im, Facebook Chat is obviously a big blow. While social.im continues to focus on building a desktop client, if Facebook doesn’t allow apps to integrate with the core Facebook chat service, it’s going to be extremely challenging for third parties to gain a critical mass of users.