Previously the only way to change the search bar in the speed dial was through using the so called power settings.
It still works the same way. And it even being discussed here.
You know: pressing up, down, up, down, left, right, left, right, b, a in your settings screen. After that sequence a dialog appeared and then several more options would become available. This no longer works.
It haven't been necessary since a long time, at least to hide the search bar.
And you can still use the Konami code to turn 'power user settings'.