Exact keyword match is remarkably high in correlation to rankings on all main search engines. On Google maybe even more then on Bing. It turns out to be one of most important onsite SEO factors for SERP ranking. On Google top 10 SERP, there are about 27% domains with exact keyword match, average. For Bing, that's about 31% in average. But since there are lots of MFA sites and lots of sites and pages with low value on Google because of this ranking factor, they may consider what they will do about this.
You can read more regarding this issue on SEOMoz article.