Players' tasks are mixed-initiative planning, sharing results of search, posting commitments by one to be used by the other. But of course, real negotiation is mostly cheap talk. No real negotiatior would commit to the inexpressive language of proposals. Speech acts run wild in negotiation because it is an essentially linguistic phenomenon, a language game. The beauty of negotiation, as Roger Fisher explains, is the creation through information-exchange of new proposals that had not been in either party's earlier ken.
Computation changes the terrain.
There is the possibility of smoothing the utility contours of the payoff matrix through information-exchange and computation. AI provides the sensitivity to computation and fluency with computation that makes such models possible. The great mathematical models of deliberation in economics were invented on the coattails of measurement theory. In the short time between von Neumann and Morgenstern and Luce and Raiffa, the time when John Nash enlivened the intellectual scene at MIT, the theory of utility swept the continent like fifth century Huns, leaving in its swath the vassal theories of games, risk, negotiation, equilibrium, and of course, decision. Now we have the formal framework for rules that Hart assumed, and it may be time to wield it on old enemies.