The official release is getting nearer. I does not hurt to read tips on your plan of attack. Some are mentioned in this article by Ed Bott
Want to make the Windows 7 upgrade experience as short and painless as possible? Follow these seven suggestions to make the process easier. (For details on what to expect, see How long should a Windows 7 upgrade really take?
) 1. Run setup from a flash drive or a USB hard drive.
Compared to slow DVDs, you can easily shave 5-10 minutes off install times. For upgrades, you can simply copy the files to the external media; if you plan to do a clean install, you’ll need to make sure the media is bootable. 2. Move massive data collections off your system drive before you start.
Copy your big digital media collection to an external hard drive and then delete the original files from your user folders before you run the upgrade. You can copy them back after setup is complete. 3. Check for compatibility problems before you start.
The Windows Upgrade Advisor runs at the beginning of the setup process and will identify any programs or devices that have compatibility issues. Resolve those issues before upgrading. (A standalone version of the Upgrade Advisor
is available from Microsoft if you want to check a system before starting an upgrade.)
more here The Windows 7 upgrade survival guide | Ed Bott’s Microsoft Report | ZDNet.com