//Code (1.7.10)

Vec3 lookVec = player.getLookVec();
Vec3 playerPos = player.getPosition(1.0F);
playerPos.yCoord += player.getEyeHeight();

System.out.println("playerPos pre-trace: " + playerPos);

MovingObjectPosition mopBlock = world.rayTraceBlocks(playerPos, lookVec);

System.out.println("playerPos post-trace: " + playerPos);
System.out.println("lookVec: " + lookVec);
System.out.println("mop: " + mopBlock.hitVec);

if (mopBlock != null) {
    int x = mopBlock.blockX;
    int y = mopBlock.blockY;
    int z = mopBlock.blockZ;
    System.out.println("Hit block: " + world.getBlock(x, y, z).getLocalizedName());
}

//Console output:
playerPos pre-trace: (7.2118501258088195, 16.261466261300132, 54.803417705774756)
playerPos post-trace: (1.904688552447381, 4.0, 14.008823309201626)
lookVec: (0.19389262795448303, -0.47477537393569946, 0.8584368228912354)
mop: (1.904688552447381, 4.0, 14.008823309201626)
Hit block: Grass Block

//View in-game:
http://ctrlv.in/698119