Peter is right. DabbleDB is awesome, Drupal can do much of what DabbleDB can do, and has been able to do so for a long time. Witness this one year old Drupal screencast. Where Drupal fails short is in making this functionality easy to use.
I still believe that it is of strategic importance that we move more of the CCK and Views into Drupal's main distribution, as opposed to keeping them contributed modules that you need to install separately. And when we do, we need to look at tools like DabbleDB, as there is a lot to learn from their user interface and interaction design.
I wish we had more people willing to make this happen. I'll be the first in line to help, because together we can get the CCK and Views to the next level.
Update: DabbleDB was acquired by Twitter and the DabbleDB website no longer exists. The link to the original demo video broke but I updated it to point to a backup on YouTube. YouTube seems to have two good videos on DabbleDB that are worth watching: https://www.youtube.com/watch?v=6wZmYMWKLkY and https://www.youtube.com/watch?v=MCVj5RZOqwY.
— Dries Buytaert