Recently we have seen many reports on browser security comparison. At least i have seen/read four such reports.
1) A Security Analysis of Next Generation Web Standards http://www.enisa.europa.eu/act/application-security/web-security/a-security-analysis-of-next-generation-web-standards
2) HTML5 the ugly http://blog.trendmicro.com/html5-the-ugly
3) Browser Security Comparison – A Quantitative Approach http://www.accuvant.com/capability/accuvant-labs/security-research/browser-security-comparison-quantitative-approach
You can split these studies under two categories:
1. Malware protection
2. HTML5 features security
Studies 1) and 2) falls under category 1.
Studies 3) and 4) falls under Category 2.
Another report on HTML web security.