"I will also throw in the fact that doing software library version upgrades on dynamically typed systems is a pain in the ass."
This is very true, but you gain a lot with dynamic languages in other areas. The last company I worked for had about 300 programmers in the office I was in. Roughly half did Java and the other half did Ruby. I was one of the few that moved between both ruby and java projects. I did not see these great benefits of static typing that people always insist exist for large teams at large companies.
"I will also throw in the fact that doing software library version upgrades on dynamically typed systems is a pain in the ass."
This is very true, but you gain a lot with dynamic languages in other areas. The last company I worked for had about 300 programmers in the office I was in. Roughly half did Java and the other half did Ruby. I was one of the few that moved between both ruby and java projects. I did not see these great benefits of static typing that people always insist exist for large teams at large companies.