Drupal 7 is going to introduce a lot of improvements, many of them regarding the user experience and user interface. in the past few days one of the greatest (and maybe the last) of these changes was committed - a new core theme, and not just a core theme but a new default theme for Drupal - that means that the mythological Garland, after almost four years, gives way to a new, fresh face for the next Drupal release.
bartik.theme, the successor, is named after Jean Bartik, one of the first computer programmers, and a woman. She worked on the ENIAC (with an all women programmers team) and the UNIVAC. and they have invented a lot of what we take for granted in the today world of computing.

While previous core themes were created by a restricted (2-3) group of developers, Bartik was created in a never-seen-before-for-a-core-theme group effort, a lot of amazing people contributed their time writing code, testing and reviewing, knowing that there is always a chance this theme will never get into core, not to mention become the default Drupal theme. I too had the honor of doing my share for Bartik - apart of helping with a few minor issues I have helped with the RTL styles of Bartik and with its unique comment form.

Bartik is not just a new default design for Drupal, this is a theme built from bottom-up to be a 2010, modern, flexible, stylish an still elegant and clean theme to go along with the awesome Seven as an admin theme and IMO even with the drupal.org redesign that flows very well with Bartik's blue-lagoon default color scheme. The concept was to create a good looking, multi-purpose theme that will keep the focus on the content, rather than on the theme itself.

Bartik brings with it a lot of improvements including the flexibility, unlike Garland, to become much more than the out-of-the-box Bartik.
Furthermore, Bartik brings the message of Drupal regions into core - that means that a lot more than just header, two sidebars and a footer are now available for you to really experience with Drupal core block module even without the use of contributed modules/themes/theming via code. another important improvement that Bartik introduces into core that for me as a hebrew speaker and for the whole drupal.org.il community is a real, a-la-tendu.theme RTL support never seen before in drupal core - that means, for example, that sidebars are flipped when you go from LTR to RTL so that the main sidebar is always situated before the content and the secondary one after, which brings us to quit the use of right and left in sidebars nomenclature, both of which might seem minor issues to an LTR person but are crucial for us RTL and Bi-directional developers. tendu.theme has, since Drupal 5, set an example for a well written Bi-directional theme and these ideas and thinking mode were slowly infiltrating core until (and we are very proud of that) Drupal 7 core itself will be the one to set the example for RTL support.

For the sake of fairness I must say that Bartik was not the only candidate for core, corolla.theme and busy.theme - both very beautiful themes were close but just not ready enough for core on the, already late, final moment. Even Bartik itself is not perfect just yet, the logic behind putting it as default now, is that this way it will get the maximum number of testing eyes so it will be as close as possible to perfect on the day Drupal 7 is released.

So congratulations to Jen, to the Bartik team and to the whole Drupal community for this achievement.
we have manage, once again, to make Drupal a little better.