Now that obviously the sanctions on Iran will be lifted in the near future after the "nuclear deal" was reached, both Airbus and Boeing will have no problem in finding buyers for their last-of-the-line A320ceo and B737NG. Airbus is overbooked anyway but could afford to allow customers who want to do so to delay deliveries and to switch to the A320neo. Boeing will find Iranian airlines willing to take B737NG's, as there are still delivery slots open in 2017 and 2018 and maybe in 2019.
The real question though is if the pressure to go to even higher rates than already announced (52 for the B737NG/MAX in 2018 and 50 for the A320ceo/neo in 2017) will now lead to quick decisions at both Airbus and Boeing.
But also Bombardier and of course Embraer could benefit from the accord: Bombardier could especially find customers for the CSeries and Embraer could sell more of their E1 line to bridge production to the E2.
Boeing also might sell some B777's to bridge their production gap between the B777-300ER/B777F and the B777-X.