Blog.SpoonGraphics Redesign...?

I'm toying with the idea of a complete redesign of Blog.SpoonGraphics, which would mean moving away from the large header illustration the site has been recognised by since 2007.

The idea behind this concept is to have a large search bar in the header on the home page, seeing as there's now 5 years worth of content (some of the old posts still being quite popular). On sub pages this would shorten right down and contain the post heading.

Do you think I should rework the existing design for "branding" purposes or would a drastic redesign be the way forward?