So here's the thing; If you want to jailbreak your freshly delivered 4th Generation iPod Touch running iOS 4.1, JailbreakMe won't help you do it, at least as of the moment.
We're 100% sure on this: iOS 4.0.1 is still the last firmware JailbreakMe supports.
What to do? Don't force the issue -- lest you want your device to suffer complications of a failed jailbreak. In the meantime, just enjoy your new iPod Touch for what it is while patiently waiting for a working jailbreak to surface.
Stay tuned for updates.