New in v14.0.x: Updated interface (Windows Live "Wave 2" inteface with Aero support in Vista), no forced Windows Live ID sign-in, various performance and stability improvements, option to disable ActiveSearch ads, slight name change (Windows Live Mail from Windows Live Mail Desktop); Release Notes - Last Updated: 08.20.09 (v14.0.8089.726)
Pros: Superb interface with separate color-coded inboxes for multiple POP accounts, supports RSS feeds, integrates well with Windows Live services
Cons: Advertising-supported, use requires Windows Live ID, currently doesn't import from non-Microsoft products