I think while they may be a scaled down version of what they once were, the WTS and JWs will exist in some form past my lifetime (I'm in my mid 40s). Yeah, they have really mismanaged things, completely over expanded while at the same time, their revenues have dropped.
When you think about it, they don't need much money to survive. I'll bet they could get by with a few hundred employees. Quit printing materials (release only online and allow JWs to print their own), get rid of all branches and have part time COs (this rumor has been floated before) that get no support from the mother ship. The overhead on the local KHs are covered by the local congregation and AHs aren't really needed since often times circuits can rent facilities very cheaply on their own.
Their biggest overhead is the printing operations which is not turning a profit obviously. They are reducing supply as a response to reduced demand but they are stuck with the fixed costs.
The religion will continue to morph but if anyone thinks its going away anytime soon, I believe they are mistaken. Unfortunately because I'd love to see it implode but it simply won't.