Chopra, who turns 80 this year, will mark 50 years as a filmmaker with the release of the eagerly awaited Shah Rukh Khan romance.
Johar said in an interview with Hindustan Times: "Yashji is like my father. His birthday this year is very special because he is probably making his last film.
"All of our films are releasing this year but that film will be the most special experience of 2012."
The first trailer for Jab Tak Hain Jaan, which also stars Katrina Kaif and Anushka Sharma, was released via Khan's Twitter feed last week and has had over 2.5 million views to date.
Johar, who recently said that he feels "talentless and "inferior" next to Anurag Basu, also commented on Barfi!'s selection as India's official entry to the Oscars.
"I am thrilled to bits, and I think what better film than Barfi! to make it. I have gone on record to say how it was truly most spectacular film experience I have had in years," he said.
"It's really everyone's wish come true that Barfi! makes it, and I hope it walks the red carpet next year."
Johar's next directorial venture Student of the Year will be released on October 19.
Watch a trailer for Student of the Year below: