As soon as I saw that there was a new Wordnik interface, I was ready to hate it. I loved the old interface so much, I just assumed that any change would be bad.
Turns out I was wrong. Now that I've had a chance to play around with the new interface, I find I quite like it. The colors, especially, are a welcome addition. And I'm pleased to see that you kept the most important part of Wordnik's visual layout: lots and lots of white space. Bravo, Wordnik gnomes! Well done!
I do have one minor complaint. Across the top of each word page is a navigation menu, consisting of the words "Love", "Define", "Relate", "List", "Discuss", "See", "Hear", and "Share". I'm glad that these navigation links are present, but I think the words that were chosen to represent each link are cryptic and confusing. (Why all verbs?) When I first saw them, I had no idea what they did, and so I was afraid to click on them.
My suggestion is that you get rid of these verbs and replace them with the names of the sections that they link to. Thus, the words across the top would read "Love", "Definitions", "Related Words", "Lists", "Comments", "Visuals", "Audio", and "Share". That way, people could tell what they do.
Love the font on Comments! The one used for comments below links is a bit hard on the eyes, though. I think someone else mentioned that it would be great if the Comments section were higher up on the page rather then relegated to the bottom half. :-)