Overall, I was very impressed by this first trailer. They managed to fit a lot into 30 seconds. I felt like I got almost as much out of it as I would seeing a full trailer as the debut, which I think was very important for them to do seeing as this was the first footage shown of the movie and it was shown to such a huge audience. The action is looking great. It looked like we'll get a good mix of dramatic slow-motion and frantic fast pased sequences. The HYDRA soldiers don't look too advanced, which is good because they have the potential to make the movie campy and too unrealistic if done poorly. The visual style of the movie and the tone are both right about where I think they should be. In conclusion, I can't wait to see more of this in a full trailer!
Click this video for my initial impressions and in depth analysis!