Currently, BrewEvent only provides access to the BrewerInventory as it is before the brewing takes place. This means that there's no way to know what the products are, without having to figure that out based on the ingredient. An additional method such as getResults (to keep the naming consistent with FurnaceSmeltEvent, I guess) would be nice to be able to get a list of products made (no null values though, please)

For consistency and convenience, it would be nice to have corresponding getFuel and getIngredient events with their future itemstacks, even though it's easy to figure those out already by just subtracting 1 from their current amounts.