Alex covered Nielsen's last figures regarding US OS smartphone shares earlier in the week, and at the time, iOS still had a slight edge over Android, with RIM's Blackberry OS still at the top.
ComScore asserts that in the time period between August and November, Android devices gained 6.4% share, while iOS devices gained a 0.8% share.
Judging from ComScore's report, BlackBerry OS still remains the most used smartphone OS, but Android has surpassed iOS by a solid 1%. However, this has more to do with Blackberry and Windows Phone users shifting to another smartphone OS, and that more of them are choosing Android than iOS, than Android taking away subscribers from Apple's iOS.
The next time these figures roll around I expect to see Windows have a decent percentage increase thanks to the launch of Windows Phone 7 devices. In addition, if BlackBerry has any hope to maintain their position as the leading platform in the US, they will have to start doing something quick to refresh their product and software offerings.
Image from Engadget