Its no S-IPS panel, but its pretty darn good for what is basically a budget laptop.
The MacBook is a budget laptop? Well, I know it has comparable specs to a $500 Windows notebook, but the price certainly isn't budget!
Anyway, the MacBook screen is good if you calibrate it. I have one with an LG display and still images look fantastic.
The real problem with all of the displays used on the MacBooks is that they have absolutely horrid response times. In the neighborhood of 24ms. You get ghosting in EVERYTHING. Move a window, mouse cursor, scroll on a web page, watch a video.. ghosting is everywhere. It's terrible. The MacBook Pros aren't much better at 16ms.
If you can stand the ghosting, then the MB, MBA, and MBP all have good displays.