Wish I could upload a screenshot. I'm seeing what appears (to me) to be a brand-new tab. There used to be just two tabs, "Keyword Variations" and "The Site-Related Keywords", but now there's a third, "Negative Keywords New!".
This is the first time you can add negative keywords right at the beginning of the Keyword Tools process, no?
...OK, played with it a little bit. It's nice, but not exactly what I wanted when I was using the Keyword Tool this morning.
The Negative Keywords tab will come up with potential negative keywords for your campaign, which is a nice feature. However, what I really had hoped it would allow me to do is to use negative keywords right in the Keyword Variations tab, i.e., tell it I was targeting, say, [card games] and then add [-pokemon]. Alas.