Zuckerberg have pledged to give away 99% of their facebook stake over his lifetime and it's quite obvious that it will result dropping up on his net worth. Keeping this apart here are few stuffs that I think Musk is the man of future.
Facebook introduced the Like button and have great influence in shaping up the social media space the way it is now. Over the past, facebook have made numerous acquisitions 62 is total and in the year of 2014 two major acquisitions, WhatsApp and Oculus see full list. From facebook’s Last F8 conference it's been clear that Virtual reality and Augmented reality is facebook's future bet.
Well in the other hand here is the wide spectrum of projects from musk,
SpaceX: Musk has stated that one of his goals is to improve the cost and reliability of access to space, ultimately by a factor of ten and at the moment offering services such as Orbit rocket launch and products like falcon reusable launch vehicles and dragon capsules. Watch Landing of falcon.
Tesla, Inc: Manufactured of electric vehicles and solar energy products. Watch self driving tesla car.
Solarcity: Specializes in solar energy services. Parent Tesla, Inc. Watch Power wall & Solar roof
Hyperloop: a high-speed transportation system incorporating reduced-pressure tubes in which pressurized capsules ride on an air cushion. Watch how it works
OpenAI: a non profit artificial intelligence (AI) research company.
The Boring Company: an infrastructure and tunneling company. Watch how it works.
Neuralink: integrate the human brain with artificial intelligence. Watch how it works.
Well this greatly concludes on how he is gonna do it.