It seems to me that the watchword is 'Relevance'. The best results are achieved by a combination of things. I.e. If your domain name and keywords and pagetitle and Content (Header tags etc..) all demonstrate that the content matches, then you will score more highly with search engines.
Incidentally - it's very possible that the new TLDs that are coming on stream will be able to help businesses to target their SEO even more.