Anyone know what/where this theme is?

I absolutely love the theme in this video:

Does anyone know what it is or where I can get it?

That’s just the default theme for Blender version 2.5.

Oh… I see on the site 2.5 is in Beta. Is it fairly stable to use? This explains why some of the stuff he was talking about, I couldn’t find in the interface. Does 2.5 represent a significant change? I’m learning 2.49, I hate to learn stuff that is soon to be out of date or changing, especially since I am starting now.