Google Video will stop hosting videos on April 29 (seen at Geekosystem). It will still serve as a video search engine for other sites, but those remaining videos that are only hosted on Google Video itself will disappear. And that's a tragedy, because there's a ton of amazing things there.
The strength of Google Video is mostly the long-play, timeless videos of talks, documentaries, interviews, and esoteric full-length movies you can't find anywhere else. As soon as you start looking you find gems like the original Nosferatu film from 1922, a talk by the creator of object-oriented programming, a long interview with Stephen Colbert out of character, or a documentary of interviews with the repentant Secretary of Defense who fomented the Vietnam War. And then there's hundreds of full-length interviews by Charlie Rose. It looks like they have almost everyone he's ever interviewed.
I'm going to say it. This is worse than Geocities.
So what I'm hoping we could all do is download as many of the good ones as we can. There's a Firefox extension that makes it really easy, and even a no-install web service that can do it for you. Then maybe we can re-upload to another site those videos that copyright will allow, or in some other way continue to keep them available. Whatever the solution is, I know that the first step is to get these videos into as many hands as possible before they disappear.
I welcome suggestions in the comments, including great videos you've come across. There's a lot to go through.
UPDATE: I've found some like-minded people leading a centralized and organized preservation effort. It requires technical know-how, but follow the instructions on this page if you want to help build a collection for the Internet Archive.
I'll leave you with an abridged list of interesting things I've found.
(Sorry they're mostly nerdy. That's why I need you to help find the other stuff!)
Night of the Living Dead (1968)
Richard Feynman - The Pleasure of Finding Things Out
Rare interview with Neil Armstrong on 60 Minutes
Richard Dawkins - Nice Guys Finish Last
GoogleTechTalks - Building a computer from logic gates to operating system
amateur video of "Buildering," a combination of bouldering and parkour
The creator of HyperCard talking in 1986
Neil deGrasse Tyson talk at Beyond Belief 2006
Talk by the creator of Narbacular Drop, which inspired Portal
note: I recommend searching general terms like "talk," "interview," "documentary," or any other interesting genre you can think of. And you can specify Google Video-hosted results by including "site:google.com" as a search term. And don't forget to check it isn't already on Youtube!