The PlayStation 3 and Xbox 360 game--previously dated for April 27 (North America) and April 30 (Europe)--is now due May 18 in North America and May 21 internationally. nope
No reason for the delay was provided, though additional details may be forthcoming through an investors conference call slated to begin within the next few minutes.
Update: Speaking on the delay during the call, Take-Two explained that the revised date provides it with a "better release window" and "more time to market" the title.
Update 2: The official Red Dead Redemption site adds that "these extra few weeks will make a big difference in helping us deliver you an experience beyond your expectations," as "we at Rockstar have always prided ourselves on the uncompromising quality of our games - and will always opt to take a bit longer to polish and fine-tune a game to be as perfect as possible when we think it necessary."