When global comes out, Center frequencies will be used a lot more. The usage of the Center frequency until now has been quite restricted, since the regions are really too small for Center to have any real effect.
However, global changes all of this. I’m not sure if this is planned or not, but I’d love for Center to have realistic jurisdiction areas. This is open on the internet, so it would just be to incorporate real life procedures.
Below is a picture of how the US is divided into 20 ARTCC’s.
Due to the incredible increase in surface area for pilots to fly on, controllers could have the option to open more than one ARTCC (how many would need to be decided when global is released, judging by the amount and density of traffic).