Just happened to me. I tried different browsers and machines. I can get to the login page after clearing cookies & cache, once I log in, poof! blank screen. For kicks, I logged in with another account (my business account) and it worked fine. Then I logged out from that account and tried my personal account again - no joy (blank page).
Naturally, even though thousands of people are having this problem today (Google stats), Facebook is in denial of anything wrong!