I think certain sets of things like looking up facts, Google Now does an impressive job whereas Siri needs to pull up web searches.
Supposedly in the iOS 6 vs Google Now demos, the iOS 6 searches are pretty good on Siri.
There's one point in the video where the user asks Siri to set timer. I think a countdown timer is far better than having a simple Android alarm.
I think Siri loses in quite a few things in iOS5, but from the iOS6 demos, it seems pretty good.
https://www.youtube.com/watch?v=kDsOtdRtG0Q
This is a good video showing iOS6 vs Jelly Bean.
Siri is very conversational, and as a result sometimes it will be very smart in prompting you for more. Look at the reminder duel in the video. Google takes you to the Alarm menu and you now have to do the rest. Siri asks you a follow up question so you can tell it WHEN you want the alarm set for your reminder.
If you notice other things like asking sports scores and the height of Kobe, Siri delivers you more information in addition to the primary answer. Google Now gives you the basics and leaves it at that.
But seriously, what's with all the Apple hate? This search stuff was released in 2011 and at that time of release, it was pretty clear that Siri wiped the floor with Google Voice Search. All Google had to do was copy Apple and here we are today. So I wouldn't call Google Now's victory a complete sweep. It's really just Siri but it's gotten a lot more searching capabilities down. As I said, if you look at iOS6, we can see huge improvements in Siri, and I expect that to keep the battle relatively even.