If you want to hear the bright side of a company, you ask the CEO. If you want to hear the challenges, you ask the COO (unless the company is failing, in which case you ask the CFO). If you want to hear the truth, you talk to the CTO. That’s exactly what the BBC did last week when they asked their customary three questions of Facebook’s Chief Technology Officer Bret Taylor. His reply was not only telling, but very likely a major revelation about where Facebook (and more importantly, people developing on the Facebook platform) is going in the very near future. What’s the Next Big Tech Thing in Your Industry?…