New bibliographical releases are available online from the Royal Historical Society. The latest update adds almost 5400 new records with about half from materials published in 2006-7.
The RHS Bibliography is available here: http://www.rhs.ac.uk/bibl.
Nearly 30% of the new records relate to Irish History and these can be found here: http://www.irishhistoryonline.ie.
The complete database which includes the Royal Historical Society Bibliography of British and Irish History, Irish History Online, and London’s Past Online (http://www.history.ac.uk/cmh/lpol) contains nearly 433,000 records.