A few points:
1. Other sports commentators have called McNabb "overrated." Just so we can keep that straight.
2. According to transcripts (I can't find a direct link) Michael Irvin says at the end of the exchange: "Rush has a point." I'm waiting for Irvin to get jumped on. Not holding my breath.
3. That being said, if ESPN in fact fired Rush, it is not a free speech issue, although some are trying to make it one. ESPN has the right to fire Rush for his eye color if they want. It's no different than boycotting the Dixie Chicks.