Apart from that, Google Talk as well as Sheets (which is a spreadsheets program), too, are experiencing their respective down times as well. You can keep track of Google’s ever growing list of services as well as their respective status here, via the Apps Status Dashboard. It is a pretty nifty tool to keep track of stuff, especially when you need to know just which particular service is up and running at that point or not.
Hopefully Google will be able to figure out just what has happened to their respective online services that are currently down, but it should not signal the end of the world, really. After all, there are way too many other services available online that will be able to offer what Google Talk does.