Good questions and I understand you asking them.
It's hard to predict the future and make absolute promises but I can't imagine ever just shutting the site down without any warning and if it was going to end, would imagine it would be a staged process - initially disable new registrations, eventually disable posting (after a lengthy period) and then have the site read-only for as long as possible. Basically, provide as much opportunity as I could for any transitioning. I can only say I have no plans to shut it down and right now cant imagine ever wanting to shut it down.
It may be helpful if I outline some of the history and my plans for the site to hopefully give you an idea of where things might be heading as it has a bearing on this.
The site was originally running on open-source forum software and over time I made various optimizations to it. As it grew, I customized more and more eventually writing my own custom software in order to keep the hosting costs under control. While there are lots of pretty good forum apps they all tend to follow the same approach and architecture and the issues you hit at scale (of both traffic and content) aren't always easy to solve in a cost-effective way and when you get to the stage where a site's hosting alone costs several hundred dollars a month to run ... well, it's not hard to imagine that can become a challenge - there's often a lot of effort and time commitment to manage things before you even get to the community and content itself.
So a few years ago I started redeveloping the site to run on a NoSQL databases which would remove a big chunk of the hosting cost and complexity (caused by using a relational database). Initially this was MongoDB but then I changed to Google's datastore (Database as a Service). This removed a lot of hosting costs and more importantly the database management issues (cost, machines to run it on, software upgrades, backups). I also switched to their Platform as a Service hosting so I literally don't have a server anymore. It is so liberating - the site scales on demand and adds instances as the traffic grows and removes them as it shrinks. No single server to fail anymore. No OS to maintain. No security patches to keep on top of etc... Again, this needed a re-write and I changed from the .NET software I had developed to one using Python.
Just removing the technical hosting issues has been a huge win and saves that drain on energy and resources.
At this stage I'd been focused on the major task of switching the datastore and the software which was a huge task in itself. So some of the features that I wanted to implement took a back seat. I also am always learning about the new platform and software in general and know I can make improvements to it.
So, the plan now is to stay on Google's cloud platform (which is fantastic) but make some tweaks to the data storage and app layer to take advantage of new technology which will allow us to improve the performance and reduce the costs. At the same time, I'll be switching to some newer front-end web-technologies to improve the performance of the app, especially for people using mobile devices. The good news is that the early prototypes work great and provide an almost complete 'installed-app-like' experience. I'm very excited.
But that's all technical ... it does feed into the forum itself though.
Part of the change has been to make the site multi-tenanted. That is, there is a single instance of the service running but I can actually host multiple forums with it. Literally one ... two, a hundred, a thousand ... it really all ends up the same thing. So one thing I'm hoping to do is to open that up as a platform to run sites on. At a more direct level this would allow for instance splitting off things into separate forums (e.g. politics) so sites can focus on their core subject more. People would be able to sign-up and create their own forum too if they wanted.
Obviously, to provide a Forum as a Service I also need to make improvements to the software for the management side of things. While I can go poke in the datastore or run scripts, someone moderating their own site would need the features provided as buttons etc... Again, I think a lot of forum software could be improved and I'm hoping to add a lot more "community / reputation" based moderation. That is, let people flag things and the software automatically remove or hide things based on the reputations of those involved. Make the forums as community-driven as possible so the moderators / owners just need to oversee things, prevent people gaming the system and not get so burnt out with the issues directly.
And that's where we are ... I'm working on building that so that the forum(s) will be self-supporting financially though ads and / or fees. At that point I can invite more people to help run the JW forum itself as it will be less effort and would have the tools they would need (and election of moderators etc... could be built in as a feature too). The only thing I would be needed for would be to manage the software service itself but at that stage I'd hope to have more people involved in the development side of things (either commercially or open-source or through interest via other forums) so if that bus did hit me, things would carry on. Obviously, everyone would really miss me ... right? (I have pictures of street parties complete with bunting, LOL).
Hopefully that helps remove any anxiety people might be feeling about this site's future. There should be some exciting improvements coming soon.