Was watching this on the news last night - and my first thought was awesome - then my second was, well what does it actually mean? Is it going to lead to anything? Can we expect vast new sciency things from this?
The most obvious advances are detection of things we can't detect at the moment..
For example, we started with light - looking through optical instruments, but then we found that light wasn't the whole story, so we started searching using things like radio telescopes and as time went on we have moved through the electromagnetic spectrum to observe and advance our knowledge of the Universe.
Now that we *KNOW* we can detect gravity waves and, in fact, they are happening all around, that gives us the possibility that we can use them to view the things in the universe that don't conform to commonly understood forms of energy or matter (Dark Energy, Dark Matter) and also let us 'look' further back into the Universes past as we are stuck in two ways - the sphere of observable light (The time it took to get from anywhere to earth and the age of the Universe) and also the fact that in the early days, there wasn't any light - it was effectively opaque.
The fact that these things are happening all the time and multiple sites could pick up the waves around the planet at (more or less) the same time mean that they can be harnessed, observed and then used to make ever more sophisticated ways of viewing the cosmos.
Who knows what they can teach us and what we can learn?