I'll be happy if they just finally renovated all the restrooms near the main gate (including the ones in the plaza, before you enter the parks).
They've renovated a few others (the one by Goldrush is pretty nice by SF standards), but those are used the most, and are the worst offenders in size, upkeep, and outdated. Yet they probably get the most use due to their location. It's a very bad first/last impression.
Oh, and more Freestyle Coke machines (especially when you consider how many gazillion people have refillable mugs now), and better upkeep of the ones they've got, as they frequently run out of flavors.