Drupal 7: Released
Drupal 7 is released. Not a beta, not a release candidate, but released. Click the Get Started link at the left of most pages on this site or go to http://drupal.org/start.
The upgrade path works like a charm (at least on the sites I've done). There are still some missing modules that are critical for some people, and that's why this site is still on Drupal 6. Once you've started using Drupal 7 and its new interface for site developers, you'll probably try to move as quickly as possible. The combination of new technologies (fields-in-core as an example) and the easier interface may further increase Drupal's use; in addition, I suspect that the trend to rely less and less on custom-written modules (and tweaks thereto) will continue.