Which states or countries have stop-sign-as-yield laws for bicyclists (Idaho stop law)?
Utah also considered it, but several groups including a large group of experienced bicycle commuters opposed the change.  The main reasons are:


It further designates cyclists as a "different" road user, possibly making it easier to limit our access to the roadway.
It has the potential of increasing the conflicts at intersections (the most dangerous area for cyclists) because cyclists can behave differently than other vehicles, and motorists may not know what to expect.


While I like maintaining momentum, and recognize that I can see farther, sooner than motorists, I believe that being predictable is more important.