You are not doomed. Instead of making a fancy, well-produced video, you can do a live interview or webinar with a simple webcam in the lead-up to the book launch. You can do this as a Hangout on Google+, or by using a screencasting service. You can interview key experts that you used for the book, experts in the field whom you know, or you can have someone interview you. Take questions from your live viewers, and show video of your face. Then, later, you can promote the replays of these interviews for people who discovered you afterward. Or make an animated video, whiteboard video, or screencast. All three create easy opportunities for hooking in an audience.