I've gone through the Social Welfare Law Reform and Pensions Bill 2006 and Section 15 deals with payment of the Pre Retirment Allowance.
In relation to the date when the Pre Retirment Allowance payment will cease - this is what the proposed legislation states:
"Notwithstanding the provisions of this Chapter and
subject to subsection (8), pre-retirement allowance shall
not be payable to a person in respect of any period of
retirement which begins on or after such date as may be
prescribed."
In answer to your question therefore, there is currently no specific date upon which payment of the allowance will cease - this is a matter for the Minister.
In addition, it seems that no new applications will be accepted after a certain date - and I believe this date has yet to be announced too and will also probably be for the Minister to determine.
If you have any concerns - I'd suggest you give your local social welfare office a call or DSFA in Longford (043) 45211.