Its not just confusing, its misleading. The marketing copy is being confused for technical terminology.

At 2880 pixels wide, the new MacBook Pro resolution is about 1.5 times as many pixels across the screen as a typical high resolution display at 1900 pixels.

> At 2880 pixels wide, the new MacBook Pro resolution is about 1.5 times as many pixels across the screen as a typical high resolution display at 1900 pixels.

A typical high resolution display of what physical size? Using the resolution is meaningless, it's the DPI that's important in this case.

Also, the 2x is not really marketing copy. It's the number of physical pixels that make up each geometric "point" in an Apple retina display. Ideally applications and operating systems would be truly resolution-independent and this ratio could be any decimal number. In such a world, you could chose how to use your screen's resolution - for more space or for smoother rendering of on-screen elements.

Apple's solution is a hack that uses an integer ratio to make backwards compatibility easier. With a 2x ratio you can blow up a point from a non-retina app to exactly 4 pixels, avoiding some hairy rendering issues.

Resolution is only thing that matters. It tells how much information you can cram into a screen. If pixels are too large move back. If they are too small move closer. If your screen is glued to the keyboard. Detach it. Like in asus transformer.

The point of these displays is to (eventually) get away from slavery to the pixel. Just because a printer can render, say, 4800 dpi, doesn't mean you want to render your body copy in a 1pt text (which it can do with better letter-shape fidelity than any of my old dot-matrix impact printers); you still print at 9 or 10 points and enjoy sharper and better-defined type. Moving to high-linear-resolution screens does the same thing—you don't cram more stuff into the screen, you cram a better version of the same stuff into the screen.

Decorative visual information is still information and how much you can fit in a screen depends on it's resolution not dpi. To enjoy smoother visuals you just have to move away a bit from big screen.

Isn't that ratio 4x then? Or am I not understanding retina displays correctly?

2x linear, 4x area. I could swear we had this discussion yesterday.

The default mode is 1440x900 doubled, hence all the talk about 2x.

Apple's standard 15" has always been 1440x900. Their hi-rez 15" has been 1680x1050.