Hi,
Make a difference between the stable and unstable version of wine can be a good idea BUT only in the package's name and not in the application's name.
For me actually, it's very complicated and it will be more difficult to resolv bug ...
Why you don't create the wine's package like from Ubuntu, it's more easy :
*** Stable Wine's package ***
wine package which include all files installed in "/usr/bin"
libwine package which include all files installed in "/usr/lib/*/wine"
*** Unstable Wine's package ***
wine-unstable package which include all files installed in "/usr/bin" without suffixe
libwine-unstable package which include all files installed in "/usr/lib/*/wine" without suffixe.
And failed the both installations. Example, wine is in conflict with wine-unstable and vice-versa.
If a user install wine-unstable package, it uninstall automatically wine package.
@Michael : I never use your package, it's a very useless (my opinion). I completly modified your "debian" folder to create my own package.