I seriously hope the amount of discontentment on this forum will make FD reconsider their decision. It might require additional time and effort, but I won't believe them if they say it's technically impossible to make the game run totally offline. Sure, you won't have injected events, dynamic markets and other online-driven stuff, but whatever, you still get the ships, the gameplay, the missions, the whole galaxy, and you can play it just like any other single player space game.
I'm sure people who simply can't play online would be happy with that. And, again, we'll all be happy with that once the servers are no longer up. This might be very long term thinking and might seem early to some since the game isn't even released yet, but it WILL happen eventually, and I know there are some nostalgic players like myself who will still want to load the game in 20 years. I mean, isn't half of this community composed of people who still love the Elite that came out 20 years ago?