Well, this is nice: Game trailer editor (and occasional Gamasutra blogger) Derek Lieu has taken the time to create an online repository of the game trailer specifications for major game platforms.
You can find it on his blog, or by pointing your browser to “gametrailerspecs.com” and riding the redirect.
Lieu has experience working on trailers for games that span the budget spectrum, and he says he plans to continue updating this repository in response to dev feedback.
While it’s not an exhaustive or perfect list (a fact Lieu readily acknowledges), it seems like a great place to start if you’re looking to produce a trailer for your next game.