I'm writing this article out myself so that others won't be so confused as to what has actually happened with Manhunt 2, so I will write it out in a list.
 Manhunt 2 banned in UK - http://www.n4g.com/ClickOut.aspx?ObjID=46390
 Manhunt 2 banned in Ireland - http://www.n4g.com/ClickOut.aspx?ObjID=46480
 Rated "Adults Only" by ESRB - http://www.n4g.com/ClickOut.aspx?ObjID=46523
 Gamefly & Blockbuster refuse to stock Adult-Only games - http://www.n4g.com/ClickOut.aspx?ObjID=46730
 Nintendo will not allow Adult-Only Manhunt 2 on the Wii - http://www.n4g.com/ClickOut.aspx?ObjID=46775
 Sony will not allow Adult-Only games on their systems. -http://www.maxconsole.net/?mode=news&newsid=18233
 Most Likely that Australia will also ban the game following UK
It seems very likely that the game will have to be heavily edited otherwise it can't come out for any of the systems it is currently slated for. The other option is to cancel the game, but with the costs involved I think Rockstar will opt for editing the game.
Just been informed by member alpharidley that Manhunt 2 has been banned in Italy too. Here is the link:
Google translated version: http://www.google.com/translate?u=http%3A%2F%2Fwww.corriere.it%2FPrimo_Piano%2FScienze_e_Tecnologie%2F2007%2F06_Giugno%2F21%2Fmanhunt_videogioco_vietato_italia.shtml&langpair=it%7Cen&hl=en&ie=UTF8