An interesting idea whereupon one switches between the Long and Short end of the Bond Market.
Now, AIM does this sort of thing with at least part of a long bond portfolio as it sells premium long bond fund shares and puts the money in short term money market funds. And the reverse is true when the long bonds are out of favor. AIMers might not get the full benefit of a "switching" system, but we certainly do moderate the long bond BETA while maintaining good overall yield.