There's a couple of things you have to understand about video embedding in most messageboard systems (including vBulletin).
1.) Video-embedding hasn't exactly been an official or built-in feature. You might see it all over the web and assume it's standard, but messageboard owners have each individually had to mod their systems to get the video-embedding capability. If a vBulletin owner knows little or nothing about modding, there is free PHP code and instructions available even if the updates subscription has expired, but mods can get very messy if you apply many of them and if they were each developed without taking the other mods into account.
2.) 4.0 will be the first version of vBulletin to include video-embedding as a standard feature. They claim to support YouTube, Vimeo, Hulu, Dailymotion, Google, and Metacafe. You won't need different tags for different video sites - you will be able to paste the full URL into the tag and it will simply work. Currently vBulletin 4.0 is in beta, and is due for full release within the next month or two.
2a.) vB 4.0 is a radical overhaul which doesn't support any 3.x templates. Whatever graphics/style/etc. we want to have for making this community look different from other communities - it will have to be redesigned from scratch. We won't be able to keep the current style.
2b.) vB4.0 costs hundreds of dollars, even if we already have a lifetime 3.x license.
2c.) We should be upgrading for other features anyway - if not for the officially-supported video-embedding.
You know Tokyo Jihen is a supergroup, when you can't blame most of the members for wanting to pursue other projects.