I think it would do more harm than good to break them up. Who is harmed by Google owning 80% of the search market? The consumer? As a consumer, I have a choice of whether or not to use Google, Bing or any other search engine and the cost to switch to a different search engine is $0. The original concept of anti-trust law is to prevent anti-competitive behavior, and Google dominates the market by having a vastly superior user experience, not by doing something to prevent me from using a different service. Given the massive amount of information they have on search history, their search function keeps getting better and better.
In terms of them offering various integrated services, I love the fact that gmail, maps, youtube, my picture gallery, etc are all integrated and can be accessed on any platform with one login.
Also, breaking Google up weakens IOS's only real competitor, Android.
I think politicians need to look at the monopolies from a prospective of what harm is being created from the Company's behavior, not just looking at market size. Breaking up Google would hurt the user experience.