1. Dictionary categories are now called tags. This should prevent them from being confused with lexical categories, particularly since it's advisable to create a tag for each category.
2. A number of dictionary features were cluttering up the mode bar. Dictionaries are, by far, the most complex and featureful things currently on the site. Several features have been moved into a special "tools" page, which has been augmented additionally with quick access to the importer and flash cards. (Also the hidden "printable" mode is included.)
3. Emoticons! go check 'em out!
Also remember to set your colour of preference
4. Pronunciation field. I've had 3 or 4 requests for this. While I wanted to wait for the SCA to be implemented before adding it (since, in theory, the pronunciation for most words would be regularly derivable from the headword form), there's no reason you should have to wait if you already have them written down.