The Developer Preview of Windows 8 was released today. I can't stress that enough: Developer Preview. This is a very early version that is full of bugs and probably won't work right on your machine. Unless you don't care about losing all the data on your computer and potentially having a huge repair bill if you can't fix your machine, don't even think about downloading it.
But, if you have an extra computer laying around, know how to create and format a new partition without losing data, or just don't care about potentially losing your music and photo collection click here to download the next version of Windows.
Click "Read More" for a video overview of Windows 8. Much of Microsoft's focus at their BUILD conference this year was on Windows, and it looks like it could be something special.