Mikko Hypponen has put up a nice Q&A blog that pretty much covers the jailbreakme issues, and summarizes several of the issues around jailbreaking in general in the process. A couple of quotes to give you the flavour:
“PDF attachments fail in iPhone MMS messages. This is also known as security through incompatibility.”
Q: Should I run an antivirus on my iPhone?
A: You should, yes. But you can’t.
Now that says it all….
David Harley CITP FBCS CISSP
Mac Virus Administrator