The version 2.x of views was released quite some time ago, and works fine for many people.
It got new features from time to time.
Then the development of views 3.x started, the port of views to drupal7 was created and a lot of new features/bug fixes/really tiny bug fixes got committed. So the development is primarily focused on views3.
Based on this views2 doesn't get new features and only critical bug fixes.