Truns out that it would be a bad idea to adopt the old 1914 standard, since it does not locate sights as accurately as weaver (they use different surfaces for locating sights and accesories) and 1913 has a poor straightness and flatness tolerance that shows up badly in new longer 1913 rails.
That is why we are adopting the NEW standard: The NATO Accessory Rail (NAR), STANAG 4694.
http://www.janes.com/news/defence/land/idr/idr090520_1_n.shtml
As the article hints, old 1913 components (made to proper spec) will be back compatible for at least ten years.
Essentially, the slot width will be the same as 1913, sights will be located the same as weaver, and all with tighter tolerances.