I know there is a project board created and stuff is being worked. The replacement for PaperUI is coming along nicely. I don’t think there is a set timeline for when testing versions will be released so I wouldn’t worry too much about it. I’ll be surprised if the first betas get released by the end of next year. But I have no real insight into what the developers are thinking.
I suspect that a similar process as was done for the OH 2.0 release will be followed. There was almost a year IIRC from the first beta to the final release and there were three beta versions I think, maybe only two. There were alpha versions prior to that I believe but I was one of those “I’m not moving until 2.0 is ready” types at that time so I didn’t pay much attention to the alphas.
There will be announcements made, similar to how the current 2.5 Milestones are announced and I like the way a separate thread is created to list and debug any problems people have with each milestone. I’d like to see that continue for the 3.0 alphas and betas.
The difference between 2.x and a 3.0 is going to be much less significant than the differences between 1.x and 2.0 so perhaps the schedule can be compressed.
The biggest areas where community contributions will be needed is in updating and testing out the docs and filing issues for any regressions or problems or feature requests.
But we all need to be patient. I’m not sure if there is a planned 2.6 release or if 2.5 will be the last 2.x version. But now that development has picked back up again after the build system move and the merge from ESH (just look at the change log for the most recent milestone) maybe there will be a 3.0 ready, or a 3.0 beta will be released in June or July of next year. But I’m just guessing. Just sit back and wait for the announcements.
For the most part, the maintainers like to stick to a monthly milestone release schedule and a twice a year point release schedule. I expect that OH 3.0 will try to fit in with that sort of release schedule as well.