I can't get on via the mobile client or on Google Plus, but I can sign in with an XMPP client or the web client on GMail.

If I send a message through XMPP, it appears in the chat window in GMail, so there's at least some actual connectivity happening. Messages aren't getting through or appearing in my logs though.

Edit: Messages are appearing in logs. My clients don't agree on who is online, though.