Keg,
As a young genex, I was at an airline where they got their first jet (my dearly beloved 727) and no-one who went on it had ever flown a jet before. They managed very very well.
I'll bet if there were no jets in the world and the 787 was the first, then JQ or anyone else would manage that well too.
The issue is choice....if you had a choice, given the brother/sister relationship b/w 777 and 787, you would choose experienced 777 drivers to be your lead instructors. Its that simple.
In no way am I putting down QF drivers....hardly their fault that the airline never ordered 777s.
I would have thought that a 767 crew would have no trouble going onto the 787. Now that Manning has gone you should all press your new CP to open up the MOU.