The chat menu us no longer visible on the main site, but it's still in the meta site menu list.
Was it replaced by blog, and if so, should it have been?
The link to chat at the top of the page gets replaced by the blog link when there's a new blog post. It'll return to its normal place in
48 24 hours, but in the meantime, you can find chat if you scroll down to the bottom of the page.
There's more information on Meta SO: