===== Variant 1 =====
Category bar gets replaced with horizontal-scrolling list of search engines. This shows up as soon as the user starts typing. Awesomebar results come in below.
http://farm5.static.flickr.com/4101/4815161491_88441b6fd5.jpg
Issue: this doesn't deal with the issue of taking up a whole row with a VKB present in landscape.
===== Variant 2 =====