IF your theory is true, and, you have to admit, this is based solely off of one desktop picture, then this new display will be somewhere between the Digital Cinema Initiatives 4K display, having a resolution of 4096x2160, which is used in and by major Hollywood movie studios...
Code:
http://en.wikipedia.org/wiki/Graphics_display_resolution#Digital_Cinema_Initiatives_4K_.284096_x_2160.29
...And 8K (Full) Ultra High Defintion Displays, which are almost at the same resolution as IMAX displays!
Code:
http://en.wikipedia.org/wiki/Graphics_display_resolution#Digital_Cinema_Initiatives_4K_.284096_x_2160.29
Code:
http://en.wikipedia.org/wiki/Ultra-high-definition_television#Resolution
Meaning, either this is exactly what I said it is, or Apple will be releasing a display in the not-too-distant-future, that only people who spend $100,000-odd, will be able to afford, which is not something that Apple does...Or, at least, not in Steve's era, and not even if Steve were still around to have a say in it!
THE MOST LIKELY EXPLANATION: Apple are going all-out with multi-display support, and this desktop picture will look absolutely perfect across 3 or so displays.