I don’t jailbreak any of my iDevices.
I see two sides of failbreaking. First, I think it is good for helping Apple figure out what power users want to be improved on iOS. The Notification Center is a prime example of that. Apple was inspired by the jailbreak community. The other side of jailbreaking is less rosy. I think many of those jailbreaking their devices is for stealing software and this is really bad for developers. People don’t mind buying a specialized coffee at StarBuck for 5$ but they don’t want to pay for 1.99$ apps. This is ridiculous.