[Yaggo]

I can fully understand why Apple promotes Safari. The demos are a showcase of bleeding edge CSS, namely 3D transitions, currently implemented only by Safari. No doubt other browsers will implement them too. See http://www.w3.org/TR/css3-3d-transforms/

Also, being hardware accelerated on OS X, Safari renders 2D/3D transitions at superior framerate compared to Chrome (don't even mention Firefox). The difference is huge. Apple's message is "Hey look, we made a great (open source) rendering engine and want show you what can be done in HTML/CSS when things are properly implemented. Check this out as a reference implementation and feel free to implement it in your browser."

[Yes, the 2D/3D HW accelerated rendering uses Apple's proprietary frameworks and is not open sourced, AFAIK.]