On tech forums there's been a lot of buzz about the good and bad of the new Macbook Pro's retina display. Some claim that images look blurry and fuzzy on the new display, due to them not being optimised for screens with such a high pixel density. Some have claimed it merely looks that way in comparison to the text and UI elements that do take advantage of the retina display, whilst others shook their heads in a disappointed fashion and removed the new laptops from their shopping cards.
Non-retina compared to retina (zoomed in). Yes, it really is just like print.
Wether the images really do display badly or not (I can't speak from experience, never used a retina display before), it doesn't take away the fact that a computer with a retina screen has entered the mainstream consumer market, and other manufacturers will soon follow.
What does this mean for designers and developers? Should you be taking retina screens into account already, or wait 'til a more substantial amount of the population is using the amazing new screens?
If you can find the time to make your projects retina-proof, I see no reason not to. Though I can't imagine the terribleness of not-retina-ready stuff on a retina display being unbearable, it's still nice to put those huge amounts of pixels to good work. If you're up for 100% flexibility, try your hand at making your own icon font. For regular images, there's a bunch of nifty ways to replace 'em with high-def ones (when available) if a retina screen is detected. Look it up, you learn more when you do the dirty work yourself!
And even if it still is a small minority that's using the screens, it's good to start developing for them. It'll make sure you know how to handle it once it becomes the industry standard, so you don't have to struggle to keep up. Besides, nobody's willing to adopt the retina screen if nothing's ready for it. It's a necessary evil if we want to put some change into the technology industry, much in the same way as with the switch from floppy disks and the likes. And if you get it right, it looks just plain gorgeous.
Keep moving forward!