Maybe just me, but seeing the entitled nastiness Scrivener gets over their Windows product, if I were Vellum, I'd hold fast.
Scrivener was originally a mac-only product. They put out a Windows version some years later, and it didn't have some (many? I didn't use it at that time so can't say) of the features of the Mac product. There was always some level of discontent over that from the Windows users, but a couple of years ago there was a major update to the Mac product and a promise that soon there would be a Windows update with all the same features. The Windows update has been delayed a couple of years now and is still in beta. Well, they're now calling updates Release Candidates. A lot of people, including me, have been using the beta for some time. It's stable and capable, but there are also a lot of users acting as if Literature & Latte, the Scriv developers, have stolen their first child, emptied their bank accounts, ought to be imprisoned for the delays, etc. There is still a Windows version you can buy that works perfectly well but doesn't have the updates of the newer Mac version. You can download (for free) the beta of the new Windows version, although you do have to update it to the next beta about once a month. There are still long threads on the L&L forum complaining, announcing they're going elsewhere, saying how people ought to be fired, etc.
L&L did make a terrible mistake in presuming it could deliver the Windows product so much sooner than has proved possible, but for me (my opinion only), seeing the threads and posts on their forum is kind of astonishing. It's not as if they've erased all the software in the world that makes it possible to write a book. Use the older version, use the beta, go to some other software in a huff.
Even so, if I were Vellum, I'd be watching this and thinking, "So glad we've been smart enough to avoid the whole Windows thing."
