Um... rationalize how you'd like, fanboys, the S3 is still better.
No reviews from the iPhone 5 but from the specs alone, the iPhone 5 is
thinner,
lighter,
faster, is made of
better quality materials and has a better overall
ecosystem.
The only advantage of the S3 as far as I can tell is its increased display size of 4.8" over 4" (correct me if I'm wrong) and the tinkering-customization aspect of Android. Altough to be fair, there are plenty of customization tweaks for a jailbroken iOS too. I'm not too much into tinkering and I haven't jailbroken my iPhone in the last couple of years, but even in the early 3GS days there were a LOT of tweaks available in Cydia.
I'm really tired of all this fanboy wars. The sad part is that, for 5 years now, I keep hearing about this "new" iPhone killer, but it feels like deja-vu already. I'm glad the competition grows closer or even surpasses Apple in some regards, but in my opinion in many areas they still have some catching up to do.
I did preorder the iPhone 5, and as you can see I also own an iPad and a MBA. But to my defence I did own the first Motorola Droid (or Milestone) and the international Samsung Galaxy S. I also have access to a Samsung Nexus. So I'm not totally ignorant towards Android.