Yep, as expected LIGO has detected gravitational waves. From a merger of two black holes ~1.3 billion light years distant from us, broadly in the direction of the Large Magellanic Cloud. The merger event was detected by both LIGO installations, one in Washington and the other in Louisiana, on 14 September of last year. This happened shortly after the "Advanced" version of LIGO went online. (It was anticipated that Advanced LIGO would detect GWs, if they actually existed, almost immediately. Which indeed happened. In fact it happened during a test run, though at full operational capability.) The observation matches the expected behavior of the merger, as derived from the equations of General Relativity, to an impressive degree. Einstein scores again (with a strong assist from astronomer Karl Schwarzchild, who in 1916 discovered gravitational waves lurking in the General Relativity equations)!
Another thing to note is that this detection not only confirms the existence of gravitational waves but also that of black holes! We already knew that the centers of galaxies contain objects of high density & small relative volume that emit no light. Now we know that the behavior of these objects, in a merger event, matches the predicted behavior of General Relativity's black hole solution. (We still don't know with any precision what's going on inside a black hole's event horizon, though…that's a task for a proper quantum theory of gravity to take on.)
So now we have a whole new way of doing astronomy, looking at the universe via gravitational rather than electromagnetic waves. There are additional LIGO detectors, spread out over the globe, due to come online in the near future. Right now we're doing the GW equivalent of looking up at the sky with Galileo's telescope. What might we find when we build detectors at the level of today's best telescopes?
-Dave-