Just installed Drupal 7 alpha 3 here's some feedback
Cant install Drupal 7 on a Mac without rebuilding your php set up, so had to install it under vmware
First thing that confused me was the default.settings.php file ( read the docs first )
Normally you rename it to settings.php and fill in your database details
Now what happens is you run the installer and it then asks you to rename the file.
I had to rename the default.settings.php to settings.php several times before it was picked up
Heres a couple of things that struck me from a themers point of view
The new admin strip at the top of the page could be a problem when building themes
The issue is when you are building a theme that needs the html and body set to 100%, for example if you are building a site with a sticky footer
Having an admin bar thats not part of the theme appear at the top of the page will throw out the calculations for the height
I havent looked into too much so im not sure if you can include the admin strip in your theme and if its themeable
Still no wysiwyg editor in core
Clients cant do html and need an editor
At the moment the main 2 editors are Tinymce and Fckeditor
Tinymce problems
Image upload is a pain
White screen of death
Javascript conflicts
Poor Webkit support
Fckeditor problems
Webkit bug when pasting text
Editor height problem in Webkit browsers