add a payroll module
It would complete the Gnucash system if it were to incorporate a fully customizeable payroll module. Possibly the people at Treshna Enterprises would allow you to work with their Paymaster software. It appears they had started a complete and open payroll software in Linux that any country could customize to fit their payroll system. I believe this approach would be well suited to the Gnuscash open philosophy!
Perhaps the people at Treshna Enterprises could make their payroll model pass aggregate transactions to GnuCash. GnuCash is a basic accounting program for home and small business, not an all-in-one business solution.