Paul: I don't quite understand what you are requesting. In 0.45, you could set the grid origin, and that would also move the ruler origin. That behavior was removed in 0.46 because you can now have more than one grid (so which one would control the ruler?), and also because that old behavior was buggy (it didn't update the actual co-ordinates of objects. See Johan's comments quoted in my comment above... Can you give some more details on what you're looking for?
Paul: I don't quite understand what you are requesting. In 0.45, you could set the grid origin, and that would also move the ruler origin. That behavior was removed in 0.46 because you can now have more than one grid (so which one would control the ruler?), and also because that old behavior was buggy (it didn't update the actual co-ordinates of objects. See Johan's comments quoted in my comment above... Can you give some more details on what you're looking for?