Case approved. Interview was a cake walk. The IO was a young African-american guy who did not show much emotions nor smiled. He greeted us with a good afternoon and walked us into a room. He swore us in and asked us to have a seat. Then he went through the entire I-485 application form and made any correction/changes necessary. He told me that I have an approved I-130 and I-140 on file but since my wife is a USC he will use the I-130 to approve my case. He said that he thoroughly reviewed the case and is approving it, but decided to ask for a couple documents just for formality - our sons birth certificate, my latest EAD card that I received few days ago, and my wife's naturalization certificate. He then took out the I-94 from my passport and handed over a signed document indicating that my case is approved and a card will be mailed to me within the next 30 days.
I asked the IO if he wants to see any photographs since I carried a few of them. He said that he has no doubt that we are married and living together and does not need any further documents. He told me that if he did not approve the case, I would get my greencard anyway through I-140 since I am current with that too, so he has no reasons to reject our case.
Finally, the IO informed us that he will add proper notes to our case that will make it very easy for me to apply for naturalization in 3 years if we just submit additional proof of our continued marriage and co-living.
Throughout the 15-or-so minutes, the I did not smile at all and was to the point, just asking what was needed. I am glad I will have a green card within the next month :-)
One advice for folks interviewing - don't show up too early. We went at 12:15 for our 1:05 interview but were not taken in until 1:15. Other couples who came after us were interviewed before since their appointment time was earlier. I guess 15-20 minutes earlier than the scheduled time would be perfect.