At first I thought I was only having problems with the style of my sidebar tag cloud. In reality:
* Dashboard dropdowns for Help and Screen Options don't work
* TinyMCE doesn't work (no buttons visible, no option to toggle visual/html)
* Can not add or edit tags
* Can not edit publication date (it actually gets stuck at the time the draft was created) or visibility (private/public)
This holds true even when I'm using default theme and no active plugins.