Don’t worry! It only affects Japan where it has been pushed back by just over a month to April 29th, MGS:PW will still be released late May in Europe and the US.
The game was originally penciled in for March 18 in Japan, but will not be released on April 29. The Western release dates will not be affected: the game will still be released on May 27 in Europe (May 28 in the UK) and on May 25 in the US.
I’m still working my way through the demo so expect some impressions on pant viewing and cloned Snakes soon.