New default theme for D7

Changing the default theme(s) was one of the questions in the survey put out not long ago by Dries Buytaert. I'm not sure if the results of that survey have been released yet; I'd be interested to know how people feel about this.

Personally, I'd like to see the table-based themes removed from the base package and some new themes introduced. Zen seems to be an excellent choice given the focus on web standards and the power/flexibility of its sub-theming. It would be great to see Zen and a few well made subthemes included to introduce more people to that theming approach.

On a related note, I think it would be better to have the administration pages use a different theme than the main site by default. The recent usability tests showed that new users have a lot of difficulty distinguishing between the administration and public areas. This would also improve some usability problems that can come about when themes work well for a site's public design, but cause problems with the backend administration forms.

Ahhh Garland
I've always had a love/hate relationship with Garland.
It does a good job at being non-ugly, flexible and customizable (with color.module), and is enough for some sites with simple design needs. Just the right balance for a front end theme.
On the other hand it's flawed as an admin theme, for a number of reasons (low contrast links, tabs-that-are-not-really-tabs, wide tables...)

While Pixture is nice, it also has technical issues we'd need to solve (table based, secondary menu is clunky...). My main gripe would also be a lack of originality: it's a basic, blocky theme. Which in itself is not bad, I'm not saying Pixture theme sucks, it looks good and is probably the best candidate I've seen in contrib (and hey, I've been a fan of Hide Ito's work for like ten years ;)
But I think we need a theme with more character to be Drupal's face for the public. Most contributed themes lack that little something that still sets Garland apart from the crowd.

So you're gonna ask me what's special with Garland? Maybe the breadcrumb container that seems to be overlap the header? Maybe the background gradient, which avoids the "content in a box" look often seen in other themes? The lack of borders around blocks? Small touches and white space make it different than the usual blocky theme.
Replacing it will be a tough job ^_^

Related notes
About the admin theme vs front end theme, I think a single theme can't do both well. So +1 for a separate admin theme.
Some people may still want to have a single theme, and there are other ways than using a separate theme to indicate if you are in admin or front, but this will be for another topic ;)

Regarding Zen, it would be great to have it (or any other good base theme) in core, but it certainly can't be the default theme. Base themes are not build to be pretty, and the official front theme needs to be pleasing to the eye. Or maybe with a very nice sub-theme that would be used by default?

Also I think keeping at least one table based theme would be a good idea. You know tables for layout are not exactly forbidden after all. And while nesting tons of tables is evil, using just one for the main layout is okay.

My two cent. +1 for ZEN in Drupal 7 . +1 Different defaults Themes for Drupal 7. but leave "Garland" as a supplementary theme, too many get struggled with trying to adapt "Garland" and they could easily upgrade to 7with their Site.

Cheers
Wolfflow