What's funny is that Google already operates as separate legal entities in different European countries (though some countries share one HQ and hence legal identity).
How they plan to further "break it up" I can't imagine.
To use a loose analogy with the Microsoft trials; msft having a monopoly on the desktop wasn't the problem. They earned it. Using that monopoly to create a second monopoly in the browser space, was the issue. Hence the unbundling.
In this case, Google having a monopoly in search isn't the problem - again, they've earned it fairly. But using that monopoly to prop up additional monopolies in, eg, advertising, is problematic.
I don't think they'll actually try to split Google up. It's so-far sabre rattling, and this decision just ensures they actually have a sabre to rattle.
But if, eg, third-party advertisers were allowed to compete with Google on Google's own properties? That'd be interesting.
I can't even begin to imagine the engineering nightmare that would be though, especially now that accounts are unified.