The Voice-Off - Android Vs. Siri - NYTimes.com

Final paragraphs of a David Pogue comparison

"Though Siri has the edge, the gap has closed substantially, and both systems are rapidly improving. For example, until recently Android had no phone-control features at all — only Web searches. And in this fall’s iOS 7 update, Siri will gain a more pleasant speaking voice, faster searches and the ability to change settings by voice (“Turn on Airplane Mode,” “Turn up the brightness,” “Turn on Bluetooth”) — something neither phone can do now.
This much is clear: Cellphone speech recognition is getting better fast. Very soon, we’ll do less talking through our phones — and more talking to them."

The Voice-Off - Android Vs. Siri - NYTimes.com