Blender's new (introduced in 2.5) UI is pretty cool. They try to have all operations available through a widget in the UI (with a tooltip), a shortcut key, a quick launch menu and through a Python scripting interface.
My favorite feature is the quick launch menu. Hit spacebar and a menu pops up, type in what you want and and it searches for operations using a fuzzy text search. It's also nice to see that you can adjust parameters to your operation and see your results live. Previously you had to enter all parameters beforehand and couldn't see the results, now you can e.g. draw a sphere and adjust the number of vertices in it, when you see the sphere.
Blender's UI has gone through a vast improvement and it's great that the UI devs have done their job well despite all the bashing they've had - I'm sure they would have done a lot more if they would have gotten more positive feedback.
Back when I started using Blender, when it was still a proprietary shareware software, most operations were only available through keyboard shortcuts that were mostly not documented. That was not a barrier for me, I quickly fell in love with the software.
Now let's hope that someone has the time to translate (more of) the manual to the new UI.
Well indeed, not very noob-friendly and not very respectful of UI conventions. However, it is reckoned that once you get use to it, it is very efficient :
No modal screen. The screen is divided. You can adjust your workspace depending on your current task. Tweaking parameters is very easy thanks to well designed widgets.
If you try, remember that you should leave your left hand on the keyboard (like a fps) and use the keyboards shortcuts.