It's PDC (Professional Developers Conference) time, and that means lots of very exciting Microsoft product announcements! (It's like Christmas for geeks) :)
Windows Azure is a new cloud based operating system from Microsoft, due for release around the same time as Windows 7. It essentially will provide the same operating system services for the cloud, that traditional Windows operating systems provide for desktops.
This is super exciting, as it's a huge change of direction for Microsoft's corporate strategy, and it shows how committed Microsoft is to constantly changing and growing as the technical world advances. It's a very exciting time for Microsoft employees and partners alike.
Ray Ozzie's keynote speech is a great way to learn about Azure, as well as Microsoft's strategy for the future. There are also other (slightly shorter) Azure videos worth looking at: