User blog comment:Godisme/The Gotei 13 repeat and reboot wrap up/@comment-3209480-20120203065015/@comment-893506-20120203065508

Probably not so much as a friend; probably more as an ally of some sort. And either way, we still don't know anything about what would drive the story of this coming arc, so we have no way of knowing what the circumstances of an alliance between Grimmjow and the Shinigami would be.