I’ve used MetaX to tag all my MP4 files, and it’s great because it automatically grabs the movie poster and IMDB info for each file and embeds it.
iTunes displays all the info when you click on the movie and formats it nicely so you can tell at a glance the actors etc. You can also search using those metatags ie all movies in 2008 or by genre, director, actor etc
The way WD TV does it by a jpg named the same as the movie file is really primitive. Not to mention time-consuming making all those jpegs manually. It’s also really nice to have the full name for a movie rather than SPIDERMAN_2. With the metatags i can have Spiderman 2 Extended Edition 2007.
If WD TV supported all those tags it would make it really powerful to display, search and order your movies. The way it is now is like DOS.