The Galaxy S3 is by all accounts an absolutely brilliant phone. There are a few factors (date released, shipped vs sold, impending release of iPhone 5 causing sales of 4s to drop), but let's not kid ourselves: Samsung is selling tons of a particular phone. This isn't just Samsung's flagship but all of Android's. As an iPhone 5 owner, I'm very jealous of a few Android features and I'm not sure if Apple will be able to keep me forever on this platform. Google Now looks like the future. Siri was the original assistant, but a truly great assistant per-empts your needs and presents you with information that you will probably want next. Absolutely a killer feature. Google's maps on Android is also the envy of the world. Google is so incredibly far ahead in Search and Services that the long term prospects don't look great for Apple. This stuff is a huge deal. Apple can't just continue to do their own stuff great. They have to hire Googly staff and become as good as Google at "Googly stuff". I don't know how you catch up to them, but Apple better try their best. iOS and iPhone/iPad win on aesthetics and user experience (IMHO) but Google's platform has a futuristic intelligence.
Apple has to be very honest with itself about where their pain points are. They also have to be steadfast on things they've done right. Microsoft's live tiles are better than Google's widgets. Apple should do a variant of that. Apple needs to start on a search engine, despite the fact that they are going to suck at it for a very long time. They need to brute force their way to feature parity with maps a clever gimmick will never come close to Street View and all Google's data.
I love iOS and have picked it over Android every time so far, but leaving the platform would not be difficult and other hardware manufacturers will catch up to Apple in its fit and finish before Apple comes anywhere close to Google for services. We can be better Apple fans when we push them to be a better Apple, and there are many areas where the are far less capable than their competition.