>>717648405 (OP)Megatexture is the proprietary name for the technique in Id's software. Virtual texturing is the generic term, and as the technique has evolved it's the name the general graphics community has adopted. A megatexture is a "sparse virtual texture".
Games need to focus on gameplay though, and while having a unique high-resolution texture for every surface in the game is cool, it's also not really that important. Especially when your game needs to scale down to consoles without a lot of texture bandwidth to throw around. Id is still using them I believe (the new Doom/Wolfensteins?), and I think Crytek incorporated them too. UE4 has them built in.