I am new to this whole football thing and I have a few questions about the impending return of ex-Eagles quarterback Donovan McNabb.  From what I understand, he played quarterback in Philadelphia for some time.  And now he plays for another team.  That's confusing...

What's even more confusing is how Philadelphians should treat him.  On the one hand, if what I have heard is true, he played quarterback (an indisputably important position if I'm reading this wikipedia article on football right) for a long time for the Eagles.  On the other hand, he now plays for a different team, the Washington Redskins.  It seems odd to cheer for him if he's on another team; but it seems odd to boo him if he has played here for so long.  Does anyone else share my state of bewilderment?  What is the proper course of action given these perplexing circumstances?