Thanks! There are no plans for an x86-64 version at the moment. The focus for me right now will be to incorporate all the great feedback we've gotten, fix the issues that have been reported and make it easier to contribute.
There is unfortunately no sample code for each chapter, but you can have a look at https://github.com/helino/aenix (the code in the book is based on aenix).
Yes. What this book leads you to is a classic UNIX-like OS - drivers in the kernel, a console, paged virtual memory. It doesn't lead you to a microkernel or a hypervisor or a cluster.
Would be lovely if someone try to something similar with Trillek's computer. should be more easy to do a little OS, as there isn't MMU, segments or privileged levels to be worried. A simple 32 bit cpu with a flat memory model, and a simple instruction set.
Me and Adam, https://github.com/tgwizard, wrote the book based on our experiences writing aenix, https://github.com/helino/aenix. If you find any issues with the text, please file an issue or open a PR at https://github.com/littleosbook/littleosbook
Please be aware that some typos and errors have been discovered, check the issues for more details!