For a little light reading while having my morning cup of coffee, I read the patent. Not only does the 58/1.4 patent show two moving focusing elements, but also the 70-200/4 shows it and mentions having two sets of moving elements for focusing.
the 28mm 1.8 and the 50mm 1.8 definitely mention the IS element.
this patent was really about the dual auto focus motors and related logic surrounding that, it didn't go into much detail of the lens design.