You’ve never seen anything like it. Because there’s never been anything like it.
Apple put this tag line at the MacBook Pro with Retina Display page at Apple.com and this amazed me to find out more on it.

A Retina display with 5.1 million pixels. An all-flash architecture. Quad-core Intel Core i7 processors. In a design that’s just 0.71 inch thin and 4.46 pounds. It’s not just the most advanced notebook Apple have ever made, it’s the most advanced Mac Apple have ever made.

MacBook Pro Retina and non-retina version comparison.
(Can’t really view the different from this small picture.)
Retina Display
This MacBook Pro have the world’s highest-resolution notebook display, a screen as vivid as your imagination. A screen where everything you see is remarkably vibrant, detailed, and sharp.
One screen. Five million pixels.
When you pack over 5 million pixels into a 15.4-inch display, the results are positively stunning. The pixel density is so high, your eyes can’t discern individual pixels. Images take on a new level of realism and text is pin sharp. And with a 2880-by-1800 resolution, you can see more of your high-resolution images onscreen with pixel-for-pixel accuracy. So your best ideas can become your best work.
More color and contrast. Less glare.
The new Retina display reduces glare while maintaining incredible color and quality. In fact, it has a 29 percent higher contrast ratio than a standard MacBook Pro display. Blacks are blacker. Whites are whiter. And everything in between is rich and vibrant. IPS technology gives you a wide, 178-degree view of everything on the screen, so you’ll see the difference at practically any angle. And you’re going to love what you see.

With a 2880-by-1800-pixel resolution, the new MacBook Pro has 3 million more pixels than an HDTV.
All-flash storage.
Another highlight is its All-flash storage. When the goal is to build the high-performance notebook of the future, it needs to begin with different foundation. For this MacBook Pro, that foundation was flash. With this all-flash architecture, not only everything more durable, reliable, and battery efficient — everything is fast. Really, really fast.

There’s a reason they call it “flash.”
You’ll notice a difference in whatever you do — starting up takes seconds, apps launch quickly, even navigating the desktop feels incredibly fluid and responsive. It’s all thanks to flash storage, which gives you up to four times the performance of a traditional hard drive.1 When you use apps like Final Cut Pro or Aperture, you can perform even the most demanding tasks right from your internal storage. And since the all-new MacBook Pro comes with up to 768GB of flash storage, you can keep all your important files with you, including large video and photo libraries. Flash doesn’t have any moving parts, which makes it superdurable and quiet. It also has the ability to stay in standby mode for up to a month. Whether it’s been 1 day or 30, this all-flash MacBook Pro will spring to life, right where you left off.
There are many more highlights such as,
- 7 Hours battery life
- Intel Core i7 Processor
- Next Generation NVidia Graphics
- Hi-Speed Ports and Connections
- Awesome Audio and Video
- iCloud
- Software that support Retina
Do find out more at http://www.apple.com/macbook-pro/features/