The existing model for Fractals of the Mists is neat but needs retuning and it looks like Arenanet has got it figured out. Currently, you can only go to a fractal that you have leveled to. For instance, a level 1 fractal player can't go to a level 5 fractal without going through enough fractals to get to that level. According to
this article, they are doing away with this issue and allowing everyone to go no matter the level. The only catch is the highest level that can be selected is that of the highest leveled player. Not a bad trade off. People will find out though that the higher difficulty level means more survival builds will be needed on characters I think.