I just ran Wprime after seeing the 4Ghz Number from the 930.
930 : 218.7 Seconds
X4 @ 4.1Ghz : 306.8 Seconds
Hyperthreading > Amd
Stick with real world tests and results Psycho, hyperthreading only helps when you are running multiple multi-threaded apps as 4 Cores with 8 threads is no faster than 4 core with 4 threads with an app that uses all of the CPU's resources.
It is 45nm. It is basically a 920 with a guaranteed DO stepping with the multi one notch higher. That is all. The price is a little higher then 920 simply because it is new item. The 930 is basically out to replace the 920.
Personally, if you're looking at overclocking then I'd stick with the 920 until stocks are gone and the 930 officially takes over.
If you're not overclocking then the slight speed boost may be worthwhile, but not at a $50 premium (it's £20 over here), and to be honest minor overclocking is so easy on the i7s you might as well just get the 920 and tap up the BCLK a touch to match the 930.
If you've already bought a 920 then stick with it.