To me big data has something to do with the fact that nowadays, when I ask people (analytics of different sorts) what they want, the sometimes say "I dont know what I want until I see it". And nowadays this maybe a perfectly reasonable respons, with information mass growing at light speed. This makes it hard to expect what amount of data we need to handle, so we need an architecure that can handle... well, any amount of data. I certainly think it can leverage the IT pros work as a political instrument.