The packager told me he solved the problem using links.
About wxLauncher, we don't need its install and update functionnalities, now we have a Ubuntu repository, fs2 open updates are synchronized with system ones. We also have a template to make mod packages for Ubuntu, it will be easy to maintain the repository.
Turey's installer, or the new wxLauncher are not made to be used as superuser, so it's more complicated to make multi-user installations of the game.
I think wxLauncher is a good thing for Windows and Mac OS X users, but it is redundant with Ubuntu package management.
And, as many people need to install retail data while installing the game, we wanted to unify the installation (free data from our repository, proprietary data from CDs or wherever else) with the tools given by our platform (debconf).
@The E: We will add more configuration options, but our goal is to make a very simple launcher, with the possibility to set advanced options by setting flags, for advanced users.