1) If you know your previous year balance i.e. Closing Balance pass one GL Entry for opening entry i.e. on 01/01/2011 and then reverse it before you close the Year
This way you will see opening Balance for new year and once you ready to close previous year reverse the same entry.
2) There is no issue to close Fiscal Year because transactions still be posted to closed Fiscal Year. With this solution no need to pass and reverse dummy entry to get opening balance.
I will recommend to go for second suggestion if you can close Fiscal Year.