We haven't seen a proof of concept yet, but given that the attack is not overly complex, it's reasonable to expect that someone will write it sooner or later.
The good news is that this problem affects only SSL 3, but the bad news is that it's still possible to downgrade modern browsers from whatever best version they support all the way down to the vulnerable protocol. (I discuss this in the "Protocol Downgrade Attacks" section in Chapter 6 of Bulletproof SSL and TLS.)
There are two things you should do: 1) disable SSL 3 in your browser and 2) if at all possible disable SSL 3 in your servers. Please refer to my blog post for a longer discussion. Scott Helme has a detailed blog post with step-by-step instructions for popular browsers and servers.
On the SSL Labs side, we released three new features yesterday to address POODLE: 1) warnings for vulnerable servers, 2) detection of the support for TLS_FALLBACK_SCSV (you'll read more about it in my blog or, better, in my book) and 3) adding detection of SSL 3 support to the client test.