Going by the trend, CAT 2008 notification is expected between 13th July 2008 (Notification is out) and 21st July 2008. 20th July appears to be the likely date when CAT 2008 notification will be out and 21st July will be the date when CAT2008 bulletins will go on sale.
How I arrived at these dates?Here you go,

CAT 2002 - Sunday, 14 July 2002
CAT 2003 - Sunday, 13 July 2003
CAT 2004 - Friday, 16 July 2004
CAT 2005 - Sunday, 17 July, 2008
CAT 2006 - Sunday, 16 July, 2008
CAT 2007 - Sunday, 15 July, 2007