Pre-orders and previews begin April 10, launches April 24.
Microsoft Piles -- er Stacks?
One feature appears similar to a rumored feature from Apple called 'piles':
- A demonstration of WinFS featured a method to "stack" documents by author in a window, with the heights of the stacks corresponding to the number of documents, as well as file views that showed snapshots of documents, rather than just file names
While the Panther Piles rumors did not turn out to be true, Apple does still hold a patent on their version of this UI element.