The day is finally here when Apple will be rolling out the iOS 4.1 to all the users through itunes. You sure are going to lose your jailbreak and unlock as you update since there’s no possible way to revert the baseband back. Hence you can possibly end up losing your phone forever unless the dev team releases the tools for iOS 4.1 which of course could take plenty of time.
Dev team states
Please stay away from this 4.1 release until a safe jailbreak procedure is developed and released.