Well it looks like the jailbreak honeymoon is over. Stories about how iPhone jailbreaking code could potentially be used to create iPhone rootkits have started surfacing.
I can't say I'm entirely surprised. Since the federal government ruled that jailbreaking was an exception to the DMCA copyright law, it has been getting coverage on major media networks like CNN Headline News. This means that more of the less tech savy users out there will join the jailbreak bandwagon, and malicious programmers will have a much larger target.
Apple really should act in the interest of their users and come up with a sanctioned jailbreak, but good luck getting Steve Jobs to agree to that.
Source: Computer World