Very interesting read.
He has a knack for creating very nice looking and relatively easy to understand slides. So by 2009, I guess he hadn't found anything better than C++. I wish he would release an updated version of these slides talking about the changes that have happened since, including maybe the viability of Rust for game development.
I did find following additional stuff:
Epic's Tim Sweeney: "We can build an economy that's bigger and better than the one in Roblox"
Epic Games boss on Roblox, monetization for Fortnite creators, training AI without permission and taking on Steam
www.thegamebusiness.com
AMA in 2023:
Facebook
Twitter