Post thumbnails & custom taxonomies

Hello all. I run a site that benefits greatly from the new post thumbnails and custom taxonomies features in WordPress 2.9, but I am looking for a way to mass edit 1000+ posts using these new features.

I was traditionally putting names in the tags section, but with the new custom taxonomies feature I have started relegating a “people” taxonomy for this use. Is there a way to mass edit posts, or shift “name tags” into the people taxonomy?

Also, I would like to mass apply thumbnails to many posts at a time. Is there a way to do this?

Thanks for any and all help!