Why is Time-Machine so overrated?

When well informed guys from PCWorld say (about Time Machine):

Innovation: Backs up changes hourly to an external drive behind the scenes, then lets you "go back in time" to restore data.

Benefit: Makes light work of the one task that every computer user should do and most people put off--and gives the function a pretty face, to boot.

Time Machine is the killer feature in Leopard. You'll either love or hate this wild and wacky space-and-time user interface, but performing backups will never be the same. One question: Why doesn't Windows Vista have anything this simple and useful?

we are forced to explain what PCWorld so well knows: Vista does have the concept, probably the usage is not as simple and evident to most users. Leopard didn't get this concept into mainstream OSs, Windows did. From Wikipedia:

The snapshot facility was first added to Microsoft Windows in Windows XP; this version could only create non-persistent snapshots (a temporary snapshot, usually used for creating a backup or more generally accessing copies of files that have been locked by applications for editing). The creation of persistent snapshots (multiple snapshots which remain available until specifically deleted from the system) was added in Windows Server 2003, allowing up to 512 snapshots to exist simultaneously for the same volume, from which maximum 64 snapshots could be used for the Shadow copies for Shared Folders feature.

Shadow Copy does exactly the same - well, except for the cool Time Machine view... We have a not so cool list of previous versions, but the versions are there, on the properties window. On an enterprise level, I believe most remote file systems on Windows 2003 are guarded with Shadow Copy, preventing the last resource tape restore - which need the presence of an administrator.

Vista comes with a simpler backup/restore strategy, but we can always setup file system versioning like on Time Machine.

In fact, this is funny: there are endless Mac forums saying that Shadow Copy copied Time Machine. And this, my friends, is only possible due to a real time machine :)