I also read that interview, and I'd like to point out that "horse trading" is an idiom that doesn't actually refer to the trading or horses (at least anymore). "Horse trading," in the sense that Dennis Shirk meant it, means to trade votes in exchange for favors.
From the inteview: "I guess it kind of does the Cold War thing a little bit as well, where two countries are really opposed without necessarily being in open conflict.
Dennis Shirk: Right. Also the way that it ties into the New World Congress to the way that youre going to have horse-trading in terms of the buying and selling of tech with other civilisations."
It seems to imply strongly that superpowers will be able to use their technology advantages to buy votes, or to support other civilizations' initiatives in return for technology assists. I'd say its such a strong implication that we can go ahead and say that there will be, for certain (100%), a way to trade technologies.