Be what's next homepage. To enable the new look, you need to visit http://www.microsoft.com/en-us/preview/default.aspx.
The layout is strongly reminiscent of Windows Phone 7's Metro UI, with not a single rounded corner to be found. There are also some design elements from Internet Explorer 9, such as the 'cut off' back and forward buttons -- and indeed, a link to the IE9 beta is front and center on the new layout. Most notably, however, the homepage features two completely different panels for both Work and Home solutions. If you click the Work tab on the right, the entire page slides over, with bars and text that reform in what can only be described as elastic beauty.
So far it seems to only be the homepage that has received the Metro treatment, but presumably, if this new layout is well received, the rest of Microsoft's Web properties will receive a similar overhaul.