Also i should clarify jic: the Mega Textures thing never meant that the textures are gonna be MINDBLOWING in terms of quality. Of course if you put your face 1 milimiter away from them they're gonna look blurry. Mega texture technology is basically clip mapping for textures. Its just one big ass texture instead of tiny ones, and it kinda just means that the game will run and look great on lower-end system since it requires much, much less specs, yet it'll look high-end. So its basically another thing to add to the constant framerate and flow they are trying to achieve.
This was already used in Enemy Territory though, but they expanded it for RAGE (and supposedly Doom 4) and now textures can measure up to 128000×128000 pixels.