Windows 8 will ship with Hyper-V virtualization software integrated into the OS. Until now Hyper-V was limited to Microsoft's server products, but now consumers (whether they care or not) will be able to fire up virtual machines without the need to download VirtualBox or some other VM software suite. Now, the average person probably won't care too much, but power users will be thrilled. And, if virtualization can be integrated seamlessly to enhance security (through sandboxing) and compatibility with legacy apps (say, via an included XP license), it could be a huge boon to casual users -- even if they don't realize it's there. For more details about Hyper-V from the Windows 8 devs, including a nice demo video, check out the source link.