One of the rumored changes is that when charging through terrain, instead of using the current method of rolling 3D6 and dropping the highest to determine the charge distance that instead it's a simple -2" to the charge distance (e.g. 2D6 - 2). So what does that do really?
Below is a graph of the probability of a particular charge distance being rolled for both methods:
Blue is the old method, Red is the new method.
But really, the odds of rolling a given range are less important than the odds of making a given charge (i.e. the odds of rolling that range or more) I've plotted those odds below:
Looked at this way, the two methods are actually pretty close.
But what about fleet? Does re-rolling 3 dice vs 2 make a huge difference? As it turns out, at 6", it's a difference of 7%, hardly game-breaking.