No, and there will never be, you might be confusing this with the updates that "brick" iPhones that have been jailbroken, but not all iPhones and iPod touches.
ya know, that is odd that you say that because last night, my phoen froze up on the net and booted me off in the middle of a post! It has never happened before, and hasnt happened since except for last night..
I'm pretty sure the entire Internet would be having a kiniption fit if there was an update that killed ALL iPhones. You'd know if that happened. It would be like one step short of an online apocalypse.