Rumours claim the next beta version of Windows 8 (and hopefully the last) is to be launched this summer. Going by the name of Release Candidate, or simply RC, this version is expected to be the last milestone before Windows 8 officially arrives. Although it's still too soon for officials to announce a changelog, leaks show improvements in the user interface area and other internal aspects as well.
Sources state Microsoft to release Windows 8 Release Candidate sometime between the end of May and the beginning of June 2012. If this happens, previous claims of a finalised version seeing light in October this year would be more than plausible.
Windows 8 RC is said to bring new features such as a tweaked user interface that allows changing colours of the background area, some light changes in the Charm bar and in the Language input menu as well as integrating the Internet Explorer 10 browser with the classic Desktop panel.
Also, the Customer Experience Improvement Program which lets users submit feedback and questions directly to Microsoft will be disabled by default.
The Release Candidate is still labelled as HB1 in the ISO tag, indicating a post-beta status of development. It is yet unknown if Win 8 RC will be made available for ARM-based processors during the above stated timeframe, or whether x64/x86 versions will be the only ones released.
At the moment, the latest Windows 8 version is Consumer Preview, which was made available on February 29th.