Perl 6 is supposed to be back compatible with perl 5

No it isn't. Perl 6 is substantially different from Perl 5. You will likely be able to run Perl 5 code under Perl 6 in some way, but new Perl 6 code is going to look very different from Perl 5 code. Worrying about Perl 6 conventions is you are writing Perl 5 is a waste of time :-)

When will all this happen? three years? five years?

When the people doing the work have the time available to make it happen :-)