Nice tutorial. I did see a few problems though:
1. Both the Virtual Box and Virtual PC sections link to the Microsoft Virtual PC download page.
2. Being a PDF is a bit inconvenient for people with browsers that require PDFs be saved to the computer before being viewed.
This happened to me as I use Google Chrome and it doesn't seem to support viewing PDFs in the browser Window.
I would suggest creating a page on the How-To Geek wiki and linking to the page from this topic if possible.
3. It would be more consistent to call the tutorial "Install Windows 7 beta to a Virtual Machine" and refer to a "Virtual Hard Drive" instead of a "Virtual Partition" as this is what the Virtuallization software calls those things.
I can fix those problems myself and upload the new version to wiki if it's ok with you. I would need the images and Word document as Adobe Reader doesn't allow easy copying though.
Edit: Thinking about it, due to the usefulness to average user who wants to try Windows 7 this may be worthy of a home page/newsletter article instead of or in addition to the wiki page/PDF file.
That would be up to The Geek to decide though.
Edit 2: One other small thing to note about the tutorial is the part "I chose not to install any security suite to save processing capacity. For one, I do not intend to do extensive work on the internet with W7, and secondly, should I catch some malware, I just kill this virtual partition and reinstall the whole system in a new virtual partition,".
That is not entirely true. If you share any folders on Windows Vista host that the Windows 7 virtual machine can access then it's possible a network aware piece of malware could corrupt the shared files.
Note: If the share is password protected and you aren't connected to in the Windows 7 virtual machine then that could not happen.