Not only can you copy invoices but also entire batches. This would be useful if you have many customers who have the same billing schedule - just set up the first months invoices for all customers, then copy the entire batch for the other 9 months.

I suppose posting future-dated invoices and their respective due dates is easy when the due date is calculated based on the invoice date, but a little more difficult if the due date is specific and independant of the invoice date. In that case, the invoice date would have to be 'tailored' so that the correct due date is determined (ie invoice date = desired due date or 30 days less than desired due date).