... if you write a piece of code for a project with a specific functionality that is requested and you finish it and the requested functionality for your piece of code has changed, then you have still written the code that was "asked" for.
If it is a problem with the fact that time changes, code changes, goals changes then fork the project, otherwise keep up the spirit and evolve with the project.
I don't think I've ever worked on a project where the end goal has been the same for anybody, small differences here and there and then the never ending "if we have this feataure, then we can do ..." and so on and then the projects evolve beyond the initial project goal... aka. "evolution".
I can't see what the problem is, yes the DBI's life in wine is a rather difficult thing, but the changes of the overall project be it open source or in the future a more commercially oriented organizational structure and environment, then it is still a piece of code in the project that is needed, from what I can understand. Commercial or not, then wine is a good thing and if the chief maintainer goes commercial, then a lot of developers would most likely abandon the project and move on to other tings or as you say fork the project.
Either way, I don't see the problem as being the maintainer, but rather an piece of evolutionary jump for the project. Wine has been very slow to gain momentum and for me the only program I use it for (or rather will) is VMWare Infrastructure Client, but not being a great hacker with the knowledge to hack wine, I'm waiting, more or less patiently :-) I'll gladly pay for wine (or the the possible fork) when it is supported to get rid of a virtual machine just to run that program.
As it is now, I think it is way out in the future, open source or commercial, so either way the problem for me seems more like an evlutionary bump in the road than a time for a fork.
Is it early monday morning and I've missed the point or is it a minor problem?