that I haven't seen anyone else mention.
1. Clearly the bot taking it to Optimus in the close up is Megatron. Notice the threads.
2. The bot in the desert looks to be the Fallen and he materializes, from where I don't know. But he starts off as a flame and becomes a bot.
3. Oh, one more. I think I have seen this, but I just noticed it. When Scorponok is flying through the air he's going after a bot holding a cane. I know a few people have mentioned Jetfire holds a cane. This either means the Decepticons fight one another or Jetfire does become an Autobot. I know Jetfire becoming an Autobot isn't news but I take everything that comes from MB with a grain of salt. You never know.
Haven't seen anyone else mention either of these yet.