The node based material editor allows you to create effect and combine different shader so easily I couldn't wonder how I would have done my shader in hlsl.

That's one aspect i like a lot, even if you can't create your ones yuo can achieve lot of things.
And you have : Normal map with specular shader working right with all in game lights directly.
Another big point, good lightmapper included in the editor, and lightampping work with next gen level( normal maps, and specular) without anything ot program or to scratch your head !
Unity shaders are also what i like a lot : just choose it in the menu on object properties: too easy and direct result !

For documentation just wait for specialised sites ?
And not sure this engine will be adopted a lot ?
UT2 SDK have not been used a lot , it was free for non commercial use, but none have done a big memorable game with it !

A downside, you won't have rights to access all UDK documentation of the official site (with Unity 3D you can), so you are limited in some way !

Anyway big AAA engine, but who indies can make a complete AAA game ?
For casual or indie or small/medium games, A7, Unity 3D , Torque 3D are they not enought and faster to learn ?

Well just wait some months to see if some indies things show up !

Yeah the mod game Airborn is impressive
But it's just very good 3D art and UT3 engine allowing good lightening/lightmaps and big levels !


On the site , in picture section you can see all 2D design , something very very important : a step that all people here skip unfortunatelly !
concept