The latest info (subject to and probably likely to change) says 50 new intakes during the 2006-2007 financial year, then well over 100 new recruits during both '07-'08 and '08-'09.
There's also an indication that there will be over 400 command positions between now and 2009 and closer to 500 F/O slots. Bear in mind many of these will be filled by existing captains and F/Os.