The iPhone Dev-Team (not the Cupertino version) hasn't wasted anytime in declaring the iPhone 3.0 operating system "jailbreakable." Just hours after Apple unveiled the latest iPhone OS, a short notice appeared on the Dev Team blog that says jailbroken iPhones will not be left out of the 3.0 party. However, the team warns those users who have the software-based jailbreak, Yellowsn0w, will have to "show some restraint" and wait for the Dev-Team's updated jailbreak tool.
The reason that YellowSn0w users have to wait is because iPhone 3.0 will modify the baseband radio. That radio is how the iPhone communicates with the network, and YellowSn0w capitalizes on weakness in the baseband radio software in iPhone OS 2.0. The Dev-Team posted its warning in part because some Yellowsn0w users may have access to iPhone 3.0 through the iPhone Developer Program. The general public will get access to iPhone 3.0 this summer.
The Dev-Team doesn't have a timetable for when they plan to release a new jailbreak tool or how long the project will take. But I wouldn't be surprised if a jailbreak solution is ready the first day of the iPhone 3.0 release. However, keep in mind that despite the Electronic Frontier Foundation's efforts, jailbreaking the iPhone is still illegal. Apple hasn't been able to do much to thwart jailbreaking recently, but that could always change. So proceed with caution, and remember "itchy update fingers and yellowsn0w don't mix!"