I think Shockey is staying in NY, and it is going to go one of two ways. Either he becomes humbled by the fact that the Giants achieved the ultimate success without him, or he winds up sulking about the fact that he is not nearly as important to the Giants as he thought.
If it's the later, he could wind up in a funk that he never gets out of as a Giant. God forbid he drops an easy catch at home and the fans start to chant BOSS. Shockey is an emotional guy, and if he is feeling sorry for himself it could lead to problems.
If however Shockey is humbled by seeing his team not even miss him during the playoffs and Super Bowl, it could be the catalyst that gets him to focus on improving his game. Up until he got hurt, I think Shockey had a very loud voice in the locker room due to his Pro Bowls, star factor and pedigree. Consequently I don't think he was held accountable for some of his actions and mistakes. Now he will be in a locker room where every guy has earned a Super Bowl ring, except Shockey.
The 1st indicator of how it plays out will be what Shockey does this Spring. If he continues his past ways by staying away from NY during the offseason, and does not come to work with Eli at any OTAs, we will know it's the same old Shockey attitude.