To be honest, Wine isn't going to be very useful and adopted until there is something that a user can install and know that if I have to update to a current verson and I pick the stable version that my apps that are running will continue to run.
Well, you perfectly summed up the 'tragedy' of Wine: nobody ever knows what YOUR applications are... There are so many Win32 applications that Wine might run one day and so many Win32 APIs and interactions between them that we cannot (and never will) guarantee that YOUR applications run from one release to the other. Heck, even Microsoft cannot do it between major Windows releases :-)
The way to solve this (as CW and TG did) is to have a 'gold / silver' list of applications and have a 'won't break' guarantee only on those.
Or to enlist all users as regression testers (without any guarantee though that the bug would be fixed). And this is pretty much the current state of Wine :-)
Lionel (who likes the 'WITHOUT ANY WARRANTY' clause in the GPL :-) )