Reader DeitysWarrior got in touch with me to give some more info on the Target situation with Manhunt 2. DeitysWarrior is the Electronics specialist at a Target location, and he confirmed that Manhunt 2 is indeed being removed from all their locations.

I made a check while I was out at Target today, and there wasn't a single copy to be found. That includes the PS2 and PSP versions.

Looks like Rockstar has quite a situation on their hands.