There is currently a case before Belfast magistrates court in which there has been application for use of the Irish language. It is currently subject to legal submission. It also seems to have piqued the interest of Iris Robinson in the Commons:
Mrs. Iris Robinson: To ask the Minister of State, Department for Constitutional Affairs how many requests for court cases in Northern Ireland to be heard in the Irish language there have been in each of the last 10 years. 
Bridget Prentice: Between the years 1996 to 2005 there is no record of any request for a court case in Northern Ireland to be heard in the Irish Language.