The next level beyond that is to shift earnings into personal corporations which are taxed at a corporate tax rate and enjoy other protections. This is like what Zuckerburg recently did.
The final dodge is to move earnings overseas much like most corporations do today.
With enough money there are always loop holes to exploit. I'm in favor of closing as many as possible. If there's someone out there rich enough to found their own sovereign nation in the Pacific, there's not much we can do about that.
The Company will begin to provide these extra perks to high income earners, solely in order to advance the Company's efficiency. Perks may include: private jet, a house near the office (or far away), fully paid for meals, etc.