It also depends on whether you made the separation official or not ~ it's a bit complicated as I don't know your personal circumstances (children, property etc) but I *think* that if you want the divorce grounds to be due to separation after 2 years, then the separation had to be applied for at court.
i have been seperated for 2 years, have no property or kids to fight over, and my husband has just sent me my copy of the petition, once i have signed that i will get my decree nisi, and after 6 weeks i will be divorced! Thats how easy!