A Snell Motorcycle Helmet is tested beyond the normal requirements of DOT testing in the US. Snell certified helmets offer a wider area of protection and perform better at higher speed impacts and absorbing and deflecting shearing / piercing forces. In October 2009 the first Snell M2010 helmets were released. While adding enhanced protective qualities, the new Snell M2010 certification does typically add a few additional ounces of weight to an otherwise DOT or ECE 2205 rated helmet. While Snell M2010 helmets are new to the market, most race tracks requiring Snell helmet certification will allow the admission of the older Snell standard for at least the next few years. We must note that there are multiple standards for helmet safety testing and each has their own set of procedures and tests. Snell is only one measurement of a helmet's ability to withstand certain types of impact.
See webBikeWorld.com for a detailed writeup on the Snell M2010 certification