The LIVE infrastructure is just like making an analogy to the network of Apple, Google, or Facebook. Once you start to build up contacts, titles, memories, etc... on one, you start to get vested as a consumer. PSN is the same now for those vested in it.
Those networks are by design to keep people within that network by playing off consumer psyche. I just used the COD crowd since it is the largest I believe. And the people will transition to new tech easier then you think. Just look how people line up and purchases new tablets, phones, gadgets, etc... that get appropriate marketing. Some may not be "day 1" but the transition to the 360 to X1 and PS3 to PS4 will be quicker then you think, unless the price is WAY outside the market segment.
May not believe me but I'm just stating this as someone who has experience in corporate finance and marketing with consumers (not with games, but it doesn't matter as consumer habits scale across industries).