In a vacuum, the Humble Bundle can't really be called a success. As I'm writing this, assuming equal split, each developer and charity gets an average of $1.09/purchase - hardly a windfall, though I'm sure the actual numbers actually favors the charities more.
But it doesn't exist in a vacuum. I wonder how much attention the involved studios'll get for future projects as a direct result of this? Aquaria, especially, has been out for quite a while now - this can probably be more accurately considered a way of breaching access to any possible remaining audiences before launching their Next Big Things.