> Cisco's patent on Virtual Router Redundancy Protocol led to the development of the more secure and more capable Common Address Redundancy Protocol

This seems like a success story in spite of software patents, not because of them. Just because they were forced to develop a new protocol in order to avoid getting sued for using Cisco's doesn't mean that they wouldn't still have improved on what Cisco had if they'd been allowed to use and modify it freely. The lack of lawsuits hanging over everyone's head certainly hasn't prevented innovation from happening in FOSS.