Please fix publish date so it may be changed!!!
After updating 2.5 to 2.5.1 and 2.5.2, it is the first thing I check in hope because it holds my sites together. I still have to edit the database 'by hand'.
The second most welcome simple change would be to put categories back to the right of the edit area. This is far better usage than Post Status (which could be reduced to a three-way toggle icon).