Apparently HTTPS is going to be standard for all Facebook users:
As announced last year, we are moving to HTTPS for all users. This week, we’re starting to roll out HTTPS for all North America users and will be soon rolling out to the rest of the world.
Great move, I’m glad they are finally getting to that point. Performance should improve over time as it appears they are on board with SPDY. I think that this will benefit them in the long run. Users win the day it rolls out.