Although I haven't spoken to Skelly about things since chat has been shut down, I think the evidence here provides all the proof that's needed over the "is the chat shutdown permanent/temporary?" question.
If you read through the comments (pay attention to what Skelly says too), a general, albeit loose, consensus was reached that stated that three weeks seemed like a good idea. Do you really think Skelly would've taken it down with the intention of keeping it down forever without telling anyone?
The community spoke. Three weeks is what is happening.
EDIT: Per the conversation below, it has been decided that a chat shutdown of 2 months would be best for the site. August 30th will now be the day that chat is reopened.
Also, I think I want to really hammer home something Skelly mentioned below: "Oh, and if the chat continues to cause problems, the next shutdown will be permanent."
Take that to heart, everyone. Chat issues really have become that serious.