I had the fortune to speak directly with people who have been through the Cisco training program, and it is pretty rigorous. Pretty impressive how they can not just answer my question about the equipment, but put it in context with how networking "works" overall.
Regarding the Facebook move - I think it's funny how people are going to try and copy Facebook here. Facebook has a very unusual business problem they need to solve, and they are very creative and clever about solving it.
A lot of folks are going to look at Facebook from the outside, ignore the unique business problem they are solving, and say "we should insource all our network gear etc." Next thing you know they have a whole mess of new problems on their hands, support and staffing at the core. I saw this with an insourced VOIP phone system. Yes, it is cheaper but when it stops working you wind up paying for support, plus the features fall behind without care and feeding over time.
The downside for the companies that aren't Facebook (or Google, Amazon) is that you can miss out on a whole range of technology that will solve your problems just as easily, with support and the "ecosystem" to go along with it. If you don't have a unique problem (and this is part of the vanity in these decisions IMHO) then you are well served to leverage the options available.