It's so exciting to see how such huge improvements happen.
I've just updated one of my 7.x websites to latest dev of views and ctools, and noticed that Views UI got major overhaul:

  1. New Views wizard

Related thread on

  1. Overall interface changes:
  1. All secondary forms are now rendered in overlay:
  1. As you may have noticed on previous screenshot, there is a quick search for fields in add-fields-to-view dialog! That's a huge time saver, even alone.
  2. No arguments anymore. Meet context filters! There are some good changes here, it's not just a plain renaming.
  3. Javascript-powered views are working fine in preview now!
  4. Views displays are not taking precious horizontal space anymore - they are moved to single horizontal bar:
  1. Loads of other improvements! Just install latest 7.x dev of views and see.

After spending some time using new interface, I can conclude that all these new improvements will help developers to save hours when working with views extensively.
The new UI is still very new, and I noticed that my Firefox 3.6 works relatively slow when live-preview is enabled, but I hope Views squad will fix most of these problems soon.

Views and Acquia squad rocks. Thank you, guys!
Here is the extensive story from merlinofchaos: