Our Guests of Honor should be people who can contribute to those conversations as leaders in new technology (especially open source!), science fiction, or related fields. They should be people who will understand that we can not pay speaking fees but will take care of them like one of our own - Neil deGrasse Tyson sends his polite apologies in advance.
We want GoHs who are advancing their field. People whose work is well-known, but also people whose work you think _should_ be well known, or could take the community by storm if they had more attention!
For 2019, our focus (like 2014's "Security and Privacy", 2015's "Human Augmentation", 2016's "Artificial Intelligence and Intelligent Agents" and 2017's "Connectivity - Social and Internet of Things") is Open Source Education.
By no means are our GoHs limited to people in this field... but if they're familiar, it will help their chances. ;)
Thanks so much for giving us your input.