Nell = The Kon character of Heuco Mundo? Maybe not. You never know. There is a chance Nell will wind up saving Ichigo's life (uh-ho, I can almost see that).

As for Grimjaw's #, I'm more inclined to believe that he wasn't reassigned a number because he actually hadn't quite settled into a "new" position yet. Hmm.. oh well, onto waiting for the next chapter!