The problem with this approach is that there are large switching costs involved (due to the previously mentioned tight coupling between javascript engine and re

The problem with this approach is that there are large switching costs involved (due to the previously mentioned tight coupling between javascript engine and rendering engine) and the "whose JS engine is the fastest" crown gets passed back and forth between Mountain View and Cupertino so frequently they should just plant it somewhere around southwest Los Altos and be done with it...