Apple released iTunes 8.2. You can download it here.
This update breaks your ability to use QuickPwn, PwnageTool, and iPhone Tunneling Suite (ssh over usb). Many file managers do not work with iTunes 8.2 installed. We don’t think this is a deliberate breakage of these tools. It’s just that Apple has updated a low-level USB protocol. It may also break Palm Pre’s connection to the device.
So if you jailbreak, we recommend you not to update.