The alpha version of Drupal 7 has been available to try out for some time now. I have been ultra curious about this release for many months after learning about significant UI enhancements that were planned. This weekend I finally had a chance to upload it to my server and take it for a spin and I was not disappointed!
Getting started
The installation process was pretty good in version 6, certain things like progressive feedback on account password fields were a nice touch. Drupal 7 builds on the same experience and adds some additional touches like site language customization, and helpful color-coded server setup messaging. (I forgot to add the settings.php file with the core upload which showed up as a red field prompting me to upload the file before proceeding.) Another nice feature was once the core files and database had been setup, I received a message stating that the setting.php file and site directory permissions had been updated and secured. (In the past you were supposed to go back and make the change on your own, but Drupal now handles it for you.)
On to the good stuff!
The first thing I noticed after visiting the new site is the large administration control strip at the top of the page. The strip organizes the main administration areas as tabs. As soon as you click a tab, a modal dialogue is presented in the main content view. All of the main sections have been carefully designed with thoughful layout and UI widgets. The overall result is a much more efficient way of navigating around the administration areas of the site and getting stuff done. At first I was a little skeptical of the heavy use of modal dialogues and Ajax from a performance perspective, but clicking around from one section to another yeilded no major lags or presentation oddities.

One of the more significant improvements to the Drupal functionality is the additional of the CCK module being built into core. For those of you who are unfamiliar, CCK, (Content Creation Kit), allows administrators to create brand new content nodes with customized content fields. Another cool feature is the customizable dashboard—the equivalent of an application start page that allows you to see things like new content, new comments, people online, etc. You can arrange the content you want to see as draggable blocks.
Despite the massive UI overhaul, I am not feeling overwhelmed by the newness of the interface. Things are categorized and named in a familiar way, and I don't think there will be much of a learning curve for relatively experienced Drupal users. If anything, I would expect the UI enhancements to make the overall experience more intuitive and easier for new users to get up to speed. Part of the beauty of the tabbed control strip is that the main admin areas are always one click away and there's no longer a sense of certain things being burried deep within the site hierarchy. With these changes I strongly believe Drupal will start to attract a much broader user audience—look out Wordpress!
Conclusion
It seems that the long wait and hard work have truly paid off for the Drupal development community, and they will no doubt win best open source CMS for a third year in a row. I plan to begin building production sites on the new version as soon as the first stable release is out and the major modules like Views and Panels is supported. I truly believe this to be the best Drupal release yet!