Stop drinking that Cool Aid, man. Yeah Apple has sold 100 million iPads, and the App Store does have a lot more apps optimized for iPads (if you're into games and stuff,) but iPad 4 is far from being the most powerful table with the best screen.
The Nexus 10's screen resolution beats iPad 4's in DPI, unless you think the marketing term "retina" actually means anything.
The Cortex-A15 processor is more powerful than A6X, and the Nexus 10 comes with 2GB of RAM vs. the iPad's 1GB. Now whether the actual apps can take advantage of the new hardware is another topic, but as far as hardware specs go, the iPad 4 has already lost its crown.
As for Surface RT being no match for the iPad4, that's 100% correct. Personally I'm waiting for the Pro version since it will run all the x86 software (I already have an old "new iPad" that I barely use, and don't need another tablet that does the same job at surfing the net or watching movies). And if the Surface Pro sucks as well, I'll just get the Sony Vaio Duo. I don't see a point in being blindly loyal to one company or one OS, especially when there's better stuff out there.