For my whole take on the Patrick Marleau contract thing, check out my Kukla's post. Yes, that's cross-promotion at its finest!
I will make this addendum (a BoC exclusive!): in sports, we've seen plenty of instances where fan outrage over "break-ups" heal pretty quickly if the team does well. On the flipside, look at the grumblings among some Tampa fans regarding Vincent Lecavalier's contract now. You'll find more than a few of them grousing about how Lecavalier should have been moved this off-season and how the team belongs to Steven Stamkos and Victor Hedman now.
So it's not an easy thing to balance out. You do it right and it's good for the player and for the team. Make the wrong move -- cut the guy off when the team still needs him or horribly overpay with term and cap hit to hinder any future moves -- and you'll be suffering for years.