Here's a page containing some info on the Godot engine:

http://okamstudio.com/tech/

I wonder why they would want to release this as open source?

It looks amazing, but I'm a little wary. It just sounds too good to be true!

It could be that the plan is to sell support contracts to medium and large developers.

I'm using it http://www.godotengine.org/forum/viewtopic.php?f=8&t=1181

Current progress http://www.youtube.com/playlist?list=PLX8H1qIvxRFUbxy_MwlGAqVWmIF16uU0F

The irc channel is helpful.

I've used it for some basic scene testing and level design, it's not too bad I really enjoy the engine, I am just waiting for more documentation and such to surface before attempting anything more serious with it, but I personally think that it has tons of potential!