What do I mean by that? Well, when you want to compare who is more popular, such as Danny Sullivan and Barry Schwartz in the search industry - you weren't able to. There is a very popular Danny Sullivan race car driver and a very well-known Barry Schwartz professor in psychology that skew the results.
Google Trends now asks you which one you mean. Here is an example, you can see Danny Sullivan shows "Editor" below his name and when I start typing Barry Schwartz, it asks if I want to use the general search term of compare it to the psychologist. Unfortunately, I am not even popular enough to show up myself as a suggestion. :)
Google explains Trends now uses and understands topics and entities, i.e. people, places and things. This way when you compare people to people, it allows you. When you compare things to things, it allows you as well. The example they gave was Rice as a food versus Rice University.
Now when you start typing into the search box you'll see new topic predictions. Type "rice" and you'll see predictions for "Rice University (University)" and "Rice (Cereal)." This makes it easy to do a fairer comparison.
I wonder if this makes the tool more useful for spammers.