Terrain appears to jitter wildly at any movement from the player when at extreme distances from the spawn. The jittering gradually intensifies as the player's distance from the spawn increases, first becoming apparent at approximately X/Z 50,000. The player model in third person view does not seem to influenced by the jittering.
Tested using the 'infinite' world type, with all view distances and graphics options. I also noted that animals move about jerkily at these distances, may or may not be related to the jittering terrain.