My niece, Susan Stromquist, created the art for the February, 2010 issue. She's Walt's daughter (nepotism, again). She, too, was working outside the box to make this image. See examples of her typical artwork on her website.
I'm not sure who was the artist who created this cover.
Amy Uyeki created the cover art for the October, 2010 issue. She is a cousin (we are a large family with many artists).
And another cover... I think Walt built this art from a diagram contained in one of the articles.