After a few days of playing and trial and error and searching, I've figured out how to do a cool new trick in TMPG DVD Author. Yes, I know it's something other programs can do, but I still like TDA and will one day take the time to use other programs (time) being the key word.
Anyway, I figured out how to make custom frames in TDA. I'll post some instructions in a few days, but you can see the results below. I made a quickie set of the New Superman cartoon and the show thumbnails are in the shape of Superman's S shield.
Each episode thumbnail plays 60-seconds of the fight with the episodes main villain.