Add a report feature like Crystal Reports that allows fully custom reports to be user generated.
This would greatly increase the universe of prospective users by including all the many Non-Profit groups that do multiple projects supported by multiple donors
Alan Whiteman commented
I believe that Gnucash can connect to MySQL and from there, one can use LibreOffice or OpenOffice to create reports that pull data from the database.
This should really be a separate project with only a data config file being provided by GnuCash. A set of common reports could be bundled with the app or available separately.
Can anyone suggest a decent reporting tool what works off an sqlite database?
If, instead the development team focuses on a true, concurrent, multi-user SQL backend, writing custom reports would be a breeze, using a variety of already existing database tools, or even cooking your own. Writing reports in Gnucash is possible now, its just very difficult. If the data were available in sql tables, people could even write their own views (using existing SQL skills) and expand the universe of reporting very quickly.