I always find it a strange and interesting thing when an MMO closes. Unlike non-MMO games, television shows, or most other forms of entertainment, if the creator stops supporting it you lose total access. That's such a weird and ultimately bad way to go, imho. I think for the long term of the industry, that has to change. Once MMO gamers have had 1 or 2 beloved MMOs shut down on them - and in the fullness of time, that is almost inevitable for most people - they are going to sour on the whole concept.
What's the solution? Well, I think MMO companies are going to have to cut it out with the closings. They are going to have to do one of three things:
1) Open source the server code. Let people run their own private servers. Include as part of the license that a server operator can never charge money for access.
2) Release a version of the server source code that allows single player and LAN. At least then people can play it by themselves or with friends.
3) Sell the game... always. Find a buyer, every single time. No matter how cheap you have to go, FIND A BUYER.
Players are going to get fed up eventually and figure it just isn’t worth their time or emotional investment to play a game that can be ripped away at the whims of some corporate bean counters.