I dunno. There is a huge movement afoot towards digital art in fantasy and sci-fi illustration right now. There are a lot of techniques that people are trying, including some produce an effect of digital material re-painted or re-illustrated.
Here is someone who's been getting a bit of work recently doing bookcovers and other illustrations that people might recognize: Dave Seeley I saw some of his "paintings" at a recent art show; as far as I can tell he assembles a collage from digital material he has collected and then overpaints critical areas with oils to give the piece a painterly feel. Then he glazes the whole thing an lays down brushstrokes in the glaze to complete the effect. Fundamentally, the piece is digital, but at a glance you might mistake it for a photo-realistic painting.
Who is the artist on the cat? If he/she has a website you can probably get an idea of how they did their work. And, while I am at it, who is the cover artist? The piece seemed similar to a Tom Kidd painting I saw; but of course everything looks different when you cut it in half for the front/back cover and reproduce it.
