O/k, why do you think you should, and how would Adobe know if you are worth inviting to speak at a conference?
The majority of none Adobe speakers at conferences are writers, or well know 'personalities' within their area of expertise. A proven track record of speaking is also required, as anyone new to public speaking will often 'lock up' during their talk. Which is why the old start small advice is often given.
Being an expert in your field is not required, as one only has to attend a few conferences to find out. Being able to put your ideas forward and keeping the attendees engaged and interested though, is a necessity.
Then we come to the Adobe products themselves, which product(s), do you write about that/those products, do you participate in the pre-release program, do you help other in,(for example) these forums, does anyone know about you, (if you work for the government, unlikely, as most try and keep a lower profile than conference speakers).