I am looking to buy the FreeRTOS hardcopy literature, am I right to assume that the newest v8/v9 changes are not covered? There are differences introduced with these new versions, how obsolete the book would be. Finally, any plan to update the documentation?
The original books are still available via Lulu. I think they were written in 2010, so while the information they contain is still relevant (everything is backward compatible), they do not cover the features added since then.
The updated book is currently provided as a pdf with all purchases of pdf copies of the original book. It is not yet available by itself, as it is a "pre-release". It is likely to stay a pre-release for a while as it needs updating for FreeRTOS version 9 now.