They found that the iPad 2 is up to four times as fast as the original iPad. But that improvement wasn't solely due to hardware improvements. To compare, they loaded an iOS 4.3 beta on an original iPad, and found that the iPad 2 was only 1.5 times as fast. This bodes well for other iOS devices receiving a 4.3 update. The iPhone 4, for example, should become 1.5 times as fast with iOS 4.3.
Comparing the iPad 2 to their Android rivals, CNET UK found that the iPad 2 was three times faster than the Galaxy Tab, and three times faster than a Google Nexus S. Considering both the performance of iOS 4.3, and the recent price-reduction of the original iPad, Android devices might experience more immediate competition from the original iPad, rather than the iPad 2.
source: CNET UK via TUAW