Well I guess LL is crazy, cause Second Life aint going nowhere and if they make a version 2.0 or 5.0 a few years down the road we will still all have our accounts.
What would be crazy would be for LL to setup a completely separate "new version" grid and require us all to re-subscribe.
We are the ones making the world here. LL merely provides us with servers.
The web was crap back in 1994, but I didn't have to sign up for a "new web" whenever someone released a new version of apache, or whenever a bunch of new websites appeared, or anything.
I've been here since Beta. The world is radically different today. I have seen SL grow from 0.4 to 1.5, from 10-15 servers to, oh 500ish, I have witnessed LL drastically change their attitude and development focus a few times. Your lifetime membership isnt going anywhere.