Well, the best solution would be to forget about a default config file and force people to configure wine correctly. If / mapping is so important for wine cfg lets have it. But I do think the best solution would be to force people to configure wine correctly, with winesetuptk that can't be considered difficult, it's easier that running the setup wizard that windows xp oem shows at first boot. BTW, we have this in the todo list
# Have wizard like app to autoconfigure wine [TODO] * proposal WineSetupTk by Jeremy White
Why not accept this proposal? Wwinesetuptk is a static binary that (I presume) only needs X to run, so no new dependencies, a few things could be better (For example it could avoid detecting ntfs partitions as partitions usable by wine), but it's a very good tool.
p.s. I'll be away for the next month, don't expect any more useless and/or irritating comments from me for a while :-)