After mega-texture engine in Rage, I hope he will try to make some immersive VR hardware. He really likes the idea, and can make a diffrence for Oculus as a company.
Actually, megatextures are shit idea.
They are shit for the usual reasons video game design paradigms are shit (because their ramifications effectively make them tightly coupled with specific design paradigm it's only fair to address them as paradigm rather than technology) - they emphasize content rather than its generation.
Techniques emphasizing content rely on just baking possibly large chunks of prefabricated content directly into the game. This generally means those chunks will be the less reusable the larger and more specific they are. This is a road straight to 4h linear derpcoasters because someone has to painstakingly craft each individual chunk of content, for example a huge-ass level spanning texture. If you have to redesign your level you have to redo all the relevant content too.
Techniques emphasizing content generation, OTOH emphasize systems that can be used to easily create large amounts of content. Pre-made content is usually broken into small, universal, reusable blocks. Those blocks may be combined and/or parametrized either by hand or algorithmically to create a broad variety of content. The actual amount of content you have to create isn't that substantial, but it's flexible and you can build higher order content out of lower order one.
Really, it's like the difference between incrementing some base integer and exponentiating it.
Tiling bothers you? Try to find a way to generate and/or blend textures in ways avoiding it being visible - scale, rotate, displace and distort multiple layers of modifier textures on top of your original one. Apply fucking decals. Generate low-res map texture automatically based on terrain type and shape then use its gradients to determine what actual detail textures use and what to do with them.
Whatever you do, don't fucking do huge texture of a level even if Carmack tells you it's awesome because he figured out how to stream it.
Carmack is the fucking dude that figured that shooting nondescript drab cyborgs who had serious trouble killing you *IF* you stood still and didn't shoot at them while running around nondescript industrial corridors, was more fun than blowing up faceless HPL-inspired monstrosities in warped gothic environments (seriously, Q2 was a dudebro GoW of its time). His judgement is just flawed.
Megatextures are fail because the underlying idea is fail. It was understandable in 1996 when you made that spiffy 3D game, but it had to run on a toaster and you still wanted pretty lighting so you made Azrael's Tear, but that was necessity. Overall the more reusable you make your content the further it will take you with the same workload.