I like things that break. I like new things. In the world of software, new things, also known as beta things, tend to break quite often, which made me and my Windows Home Server backups a little too familiar with each other.
Enter Windows 7 and Boot from VHD.
Now granted, I could've always dual booted, but a dual-boot system is sort of a big commitment. That disk space is gone, and there just isn't an easy way to get it back. With boot from VHD, if I need it, I dump it on my hard drive, if not, I can shuffle it off to larger stores without losing all my setup time. I can get it to a state I like, then copy that off for safe keeping, like after I've loaded Visual Studio 2010 Beta 1 on it, but before I've done something hideous to the OS.
Scott Hanselman has a post with a pretty decent guide that covers the basics of boot from VHD. Read all about it here.
Also, for the record, I never use any fancy Windows 7/Windows 2008 R2 install media tricks to install an OS on a VHD. Download the Windows AIK and be introduced to the joys of ImageX. With ImageX, you can select the Windows install image (from the source media install.wim), and lay the bits down on the VHD without having to run through the full installer. First boot, it's very similar to a sysprep experience.
Windows 7 FTW!