Knowing that Microsoft wants to spread Windows 8 to the public, they must release it during a good time. Likely, Windows 8 RTM will be released in the fall right before school and winter shopping. Partners such as Asus have already shown off demos of Windows 8 Tablets. Until then, the release candidate is being tested and refined to optimize the user experience, especially the mouse and keyboard input.
Example of the new Windows 8 Metro Start Screen