No one should be surprised that Facebook considers Google a competitor, and while I don't think they are 'terrified' I don't think anyone is still thinking this is a 'half hearted' effort by the big G to move in on Facebook's turf. Its 'game on' as they say and let the most agile win.
Looking at Facebook's arsenal of existing properties, combined with their large installed base advantage, and a bit of 'coolness' advantage too, the situation isn't as dire as TC would want you to believe. It does mean they will need to bring their best game to this particular dance. And somewhere in Facebook headquarters there should be a 'war room' where the folks who are co-ordinating this particular response are sharing strategies, making plans, and contingency plans, and feeding that back into the company and following through to make sure the company is executing on all cylinders.[1]
Of course that isn't rocket science, its management 101.
[1] I count the mix of metaphors at 3 sort of a sports-social-vehicular motif :-)