Microsoft counts back big on the user feedback for any of their product. The reason their beta program is so strong is that they push the betas, alphas for as long as 20% of the product development cycle. Windows 8's success too will be dependent, primarily on the user feedback and changes made to encounter those feedback.
One of the nice things Microsoft did with Office suite was to provide a feedback tool inbuilt. And over iterations that tool really helped them improve their product. If you are using Windows 8 Dev Preview and want to submit the feedback you can install the Windows Feedback Tool from the Connect Site associated with your Windows Developer Preview program.
If you're a MSDN subscriber, the information on how to join the Connect program is included on the download page where you installed Windows Developer Preview. There's a link to the Connect site and an invitation code that you can use to join using a Windows Live ID account.
After the installation of the Windows Feedback Tool:
- Open the Send Feedback icon on the Start screen.
- On the left side of the window, select the category for your feedback like “Appearance and Customization.”
- On the right side pane, from the given list choose the issue that matches your feedback as closely as possible, and then click/tap Next.
- Add some descriptive subject to your issue like “Windows hangs after installing updates etc”
- In the consecutive steps describe the flow how you arrived this issue. Try to describe all last steps as closely as you can to help the Windows team reproduce the problem.
- Review the information being reported about your system. Add any additional details, screen captures or files necessary to reproduce the issue and click/tap to Send Report.
And you are done. Congratulations you have helped towards getting a better software product.