At http://phys.org/print331284112.html … the claim that gravitational waves from shortly after the Big Bang had been detected has turned out to be a dud squib. It seems the hullaballoo was premature.
Polarised microwave light in the Milky Way is produced by dust grains that spin on their axes and align like a mini compass with the interstellar magnetic field. The dust grains line up in the same general direction and this produces polarised light – exactly the same thing as theorised would have been produced by gravitational waves from the early universe.
The PLANCK mission of the ESA has been mapping our galaxy and they have produced images of the gas and dust. This has nothing to do with the microwave background and is entirely a process of collecting data from near space. It seems the BICEP team used a model of the gas and dust rather than the actual maps from ESA (which are still in the process of being brought together for research purposes). They appear to have underestimated the foreground emisson from dust and therefore overestimated what they thought was gravitational wave detection. Another bit of modelling down the chute.