The new site looks and (mostly) works great. Flat, responsive design is very of-the-time, and will feel very 2013 for years to come (just as the old design felt 2005 eternally.)
The problem I see is that it is a) hard to navigate and b) different from the old social paradigm. It will take a while for people to get used to the changes because while usability of the CREATION social features has improved, CONSUMPTION (the part most of us pay for) is now more difficult.
I assume the design was done internally; if not, I sigh wish I had pitched this work!