Yes, I believe they are engaged now (can't find a confirmation link though).
Also, I think a lot of people need to remember the movie only goes through 2005-ish when they got their 1,000,000th member and Sean Parker was forced out after the cocaine bust (which I gotta believe did not happen in the same day like the movie portrayed). This movie does not touch anything about current day Facebook and all the recent privacy issues or anything. It focuses on the ramp up and all the hurdles Zuck crossed to get there (regardless of whether he created those hurdles for himself or not).