I downloaded the 1080 version of the teaser from youtube in mp4 format and used VirtualDub to extract the images. I extracted every single frame from the video (over 1.5 GB of images) and then picked out the ones I liked.
Normally I use Sony Vegas for video editing but since I was just extracting the frames I chose to use something quicker.
Thanks! So you downloaded the compressed mp4 with a browser plugin I take it? It would be cool to get our hands on a really nice HD h.264 or matroska quality copy. Still virtual Dub is a great tool. I've only used it a little to hardcode subtitles into video for tech-illiterate friends but it seems to be very flexible.