This is a downright awesome concept, and if the developer created even a single "average joe" install for a very specific case (say, LDAP for local machine only with easy access for Thunderbird) I think people would start considering this. There are many Mail.app users who would like to switch to Thunderbird but also want OS X's Address Book. The advanced LDAP stuff could still be accessible to the advanced users with some instruction.

Example of the problem... Look at Privoxy. Pretty darn easy to install; takes just a minute to modify the browsers to use it; works pretty well with no custom configuration. All this, yet only a small fraction of a percent of Mac users will ever consider using it because it is "too hard" to understand.

30 minutes for an install/setup (for highly advanced users) is simply unacceptable. Until that is dropped ten-fold, don't expect more that a smidgen of customers willing to even try it.