I tend to think that Retina on larger screens (iPad sized and larger) still a ways off for cost and gpu/battery reasons.

I mean, doesn't a 30" monitor require dual-link capability to feed that resolution? A retina display on even an iPad sized screen would approach that type of resolution.

DisplayPort tops out at 17.28 Gbit, which is enough for 4540 x 2837 at 60 Hz. At iPhone 4 DPI (326), this would be a 17" screen.

The dual-link thing only applies to DVI, which Apple doesn't even use externally anymore, let alone internally. Also, the success of AMD's Eyefinity shows that modern GPUs can handle very high resolutions effortlessly for anything other than complicated 3d rendering. 2D and simple 3D (of the sort that might be used by a compositing window manager) are too easy.

The only limitation is that producing very high DPI displays in large sizes with acceptable defect rates is extremely expensive.

A 15" laptop would need something like 4000×3000 pixel to equal the current iPhone’s resolution. (A 30" screen would accordingly need something like 8000×6000 pixel.)

I don’t even know whether that‘s currently feasible below the price of a small car or something like that. I wouldn’t expect 300+ ppi (“Retina“) screens anytime soon but resolution independence sure would be nice. (And later maybe some 200+ dpi screens.)

A Mac "Retina" display wouldn't necessarily have to be 326 dpi like the iPhone 4's: computer displays are usually quite a bit further away from the user than iPhone displays.

Dual link is DVI terminology isn't it? Apple use DisplayPort now. I'm not sure what bandwidth concerns devices with integrated screens have.

Oops. All I meant was that the processing of all those bits would eat a lot cycles. It came out incorrectly.