And I hope he will write a similar book for Perl 6 some day

And I can certainly see myself writing a book on Perl 6 best practices. But I can't see myself writing the best practices book until I have 5 or 10 years experience of what people do wrong in the language. That's where the best practices come from. Seeing the mistakes that people make and the consequences of those mistakes...and we don't know what they are yet. To write Perl 6 best practices needs a lot of experience in the community, and a lot of feedback, and me teaching a lot of people and finding out what they don't do right.