Smartphone OS: a "three-way tie"

Now that the race has picked up some momentum, Which Smartphone OS is the winner at this point? According to Nielson, its a three-way tie, between Apple iOS, Android and RIM's Blackberry OS. This is based on installed base (ppl who already own a smartphone) so we might be seeing the Android numbers pick up soon. But the Verizon iPhone is here. You never know ..

Statistics Source: Nielson