MacWorld's Peter Cohen has written an article on "DisplayPort, What you need to know".
The Mini DisplayPort found on new MacBooks, the refreshed Macbook Air and 15-inch MacBook Pros replaces the DVI and mini-DVI interfaces found on older models. But is this another proprietary debacle like Apple’s failed Apple Display Connector (ADC) interface? No.
DisplayPort is, in fact, an open industry standard promoted by the Video Electronics Standards Association (VESA), the same group that determines standard sizes for flat panel display mounts, for example. And Apple isn’t the only company supporting DisplayPort. HP, Philips, Samsung, Lenovo, AMD, Nvidia, Intel and many other companies have thrown their weight behind the standard, so we’ll be seeing a lot more DisplayPort-compatible devices in the coming years.