In addition to AWA, Sakura-Con (Seattle) has an "Other" category for non-anime videos, as well as a separate contest for original animation. This was true for the past two years, but may not be the case next year. Like jbone says, you need to check the rules for each contest.
(Last year's "Other" category had videos that used Titan A.E.
and Dragon's Lair
I don't think the rules are up yet, but you can check here:http://www.sakuracon.org/
For 2003 I will not be having an "Other" category. My rules do state though that a percentage of the music video must have anime content.
Dictionary.com states that the definition of "anime" is:
A style of animation developed in Japan, characterized by stylized colorful art, futuristic settings, violence, and sex.
and it states that it is a shortened word for "animation," and its definition is:
The art or process of preparing animated cartoons.
An animated cartoon.
So technically, my rules do allow for non-Japanese origin animation, but the rules also do state that interpertation of the rules is up to me.
BTW, the rules are finalized and have been submitted to the Web Page Team to put up on the Sakura-Con Website. In other words, they should be there shortly...