The facial hair isn't exactly a fashion choice. It's part of Movember, an annual, world-wide charity movement dedicated to changing the face of men's health- all through the power of the moustache during the month of November (get it now?).
Men start clean-shaven on Movember 1st, then grow a moustache or beard for 30 days while raising funds and awareness for men's health, specifically cancer affecting men in the US.
Since it's beginning in Melbourne, Australia in 2003, Movember has grown into a global movement, with more than a 1.1 million participants raising $174 M USD to date. In the US, Movember raises funds for its men's health partners, the Prostate Cancer Foundation (PCF) and LIVESTRONG, the Lance Armstrong Foundation.
No word on if he's going to shave the beard off after today. It is finally getting cold out, so maybe he wants to keep it for the warmth?