What do you call someone who is able to learn the new technologies?
Solution 1:
George is highly enthusiastic and adaptable with the latest technologies and advancements.
Adaptable: able to change or be changed in order to fit or work better in some situation or for some purpose : able to adapt or be adapted.
Solution 2:
It may not be the most precise answer as it relates more closely to an understanding of existing technologies, but tech-savvy makes some implication that a person would be capable of learning new technologies as well, and it's perhaps the most apt single-word choice.
George is tech-savvy, because he knows the concepts well.