At a layman level it gives you an indirect measure of what a gravity wave would look like.
So the chances of the Ligo detectors seeing a gravity wave just went up by many thousands fold because you can at least sort of calculate what you might expect it to look like so Bill will be happy
You will note Jester gave you the big warning.
It is worth remembering that the gravitational waves during inflation is the most plausible but not the unique explanation of BICEP results. For example, an early phase transition or decay of massive particles during inflation may also generate tensor perturbations. That's another model building direction worth following in the coming weeks.
There is stuff to work through and ultimately it may need LIGO to settle it.
Significantly if verified it also says GR is correct and was there as near to the start of the big bang as we can get. It also means with a very high probability gravity is quantized.
Lubos does a really good analysis:
(
http://motls.blogspot.com.au/2014/03/bicep2-primordial-gravitational-waves.html#more)
Gravity is not my specialty but almost all the science sites will be carrying details throughout the week however as the discovery is on par with the Higgs, so hit them for more detail.
