Apple has added 300 new emoji to the iOS 8.3 and OS X 10.10.3 betas, but they're focused almost exclusively on inclusivity — diversity in skin tones and country flags. The watch, phone, and computer emoji have been redrawn to match Apple's current products, but it doesn't appear that any of the new Unicode standard emoji have been added. Paul Kafasis, writing for One Foot Tsunami:
None of the emoji from the updated Unicode 7 spec are included. Apple continues to flip us the figurative bird by refusing to provide us with a literal middle finger. Diversity of races is surely a good thing, but where is the diversity for people who wish to communicate with widely recognized hand gestures? Surely we deserve satisfaction!
Apple might be too family-focused to include the "middle finger" emoji, but there are 250 in total that could be interesting to add, including the "live long and prosper" Vulcan hand, "joystick", "cloud with lightning", and many more.
(Sadly, "tacos", like "poutine", haven't yet passed the proposal stage.)
iOS 8.3 is still in beta, and iOS 8.4 and iOS 9 are still forthcoming, so it's possible we haven't seen the last of the new emoji. While 250 is a huge number, a lot of them are variants that could be accessible through a long press gesture the way the skin tones are implemented now.
P.S.: In case you're concerned about Apple spending time on emoji instead of fixing whatever bug is bugging you most — the person drawing emoji isn't the person who's tasked with fixing your bug. Messages is the most popular app on iOS, and adding fun things like new emoji has relatively little impact on production, but a huge impact on our ability to tease and troll each other.
If, like Paul, you'd like to see more of the new emoji from Apple, you can dupe his bug report via rdar://19925942.