All you need to know about Technical and Hidden Machines.
All TM/HM's are TM'sEdit
There are no longer Hidden Machines, there are 100 TM's. Much like Gen 5, all TM's are re-useable, and contain various powerful moves. There is no longer a need for Hidden Moves.
No more HM'sEdit
All of the Hidden Moves, such as cut, surf, flash, rock smash, etc, will be replaced with tools such as an Axe, collapsable surf-board, flashlight, hammer, etc. The player recieves these Key Items at certain points in the gamebefore they are needed. If you need it, you'll have it.