Microsoft just released the Windows 8 Consumer Preview.
You can download the Windows 8 CP from here.
Product key: DNJXJ-7XBW8-2378T-X22TX-BKG7J
There is also a detailed guide about the new and improved features in Windows 8.
- AppLocker
- BitLocker
- Windows to Go
- Measured Boot
- Client Hyper-V
You can download the guide from here
As you might notice while downloading, the x64 image is around 3 GB. The Microsoft download servers will have busy times during these days.
Remember back in the old days Windows 95 was just 19MB 