OK, I take this one back, but only because wikipedia fixed the problem on their end. If you do the Google Omni-box key-word > tab > search term it formerly work

OK, I take this one back, but only because wikipedia fixed the problem on their end. If you do the Google Omni-box key-word > tab > search term it formerly worked only with a single search term. If you tried searching for "casey jones", for instance it broke because the omni-box only creates a url, it doesn't use the site's native search engine. So you end up with "%20" between the terms. Apparently wikipedia saw this problem enough times to build in the smarts to redirect to "casey_jones".