Apple just dropped iTunes 9.2.1 on the official website. This version should be jailbreak-safe, but you should not update yet, until the community confirms it 100%.
New in iTunes 9.2.1:
- disables older version of some incompatible third-party plug-ins
- addresses minor issues with dragging and dropping items
- addresses a performance issue when first syncing to some devices with iTunes 9.2
- addresses an issue upgrading to iOS 4 on an iPhone or iPod Touch with encrypted back-ups
- addresses other isses that improve stability and performance