Call me old fashioned, but I like the way Drupal 6 works. One of the main complaints about Drupal was that there was no dedicated admin section, as there is in Joomla or Wordpress. (I'm assuming for Wordpress, as I haven't used it for more than a few hours). This was overcome with modules, separate admin themes, etc. for those who wanted it. However, I'm not sold. The admin section was under the navigation section, easy to see, easy to read. It was split up into sections, with those sections grouping similar items. It works.
I wouldn't quite say that Drupal 7 has done to Drupal what Word 2007 has done to Word, but I'm hesitant to take the plunge just yet. At what point is the UI overthought? At what point do you bow to other platforms in order to build a bigger (but not necessarily better) community? If Drupal is moving to this new UI in order to speed up administrative tasks, I'm on board. If they/we are moving to this UI in order to make Drupal more like the other projects, then we're doing it for the wrong reasons.
Now I, as a part-time Drupal enthusiast, have very little say in what really goes behind the scenes. I code very little PHP, I have yet to contribute to a production module (although I have submitted a few bug reports and feature requests), and I don't spend a lot of time in the forums or groups. So my opinion means just slightly more than people who have never heard of Drupal. However, I'm just now getting the feel for it, and the AJAX-y stuff is just... too much.