At its Worldwide Developers Conference 2012 June 11-15 in San Francisco, Apple (NASDAQ: AAPL) took the covers off the latest versions of its ultra-thin MacBook Air and the MacBook Pro 15-inch, which now comes with the same high-quality retina display found on the company’s iPhone and iPad tablet.

It doesn’t take much to excite Apple fans (or the media, for that matter), and so far WWDC 2012 hasn’t disappointed, particularly in the case — or casing, as it were — of the 15-inch MacBook Pro, which is now almost as thin as Air, literally. The latest MacBook Pro features the latest Intel Core i7 quad-core processors with Turbo Boost, Nvidia GeForce GT 650M discrete graphics and up to 16GB of faster RAM and up to 768GB of flash storage. The notebook starts at $2,199.

The Air, available in 11-inch and 13-inch designs, features a new FaceTime HD camera that delivers high-definition 720p, along with faster processors, graphics, memory, flash storage and USB 3 connectivity.

The 11-inch Air comes with a 1.7 GHz processor, 4GB of memory and is available with 64GB of flash storage starting at $999, and 128GB of flash storage starting at $1,099. The 13-inch MacBook Air comes with a 1.8 GHz processor, 4GB of memory and is available with 128GB of flash storage starting at $1199, and 256GB of flash storage starting at $1,499.

Hardware wasn’t the only area where Apple was making a splash, announcing the availability of OS X Mountain Lion, the ninth major release of Apple’s desktop operating system, available in July as a download from the Mac App Store.

The OS contains more than 200 features, including an upgraded Messages app, Notification Center, systemwide Sharing, Facebook integration, Dictation, Power Nap, AirPlay Mirroring, Game Center and the enhanced security of Gatekeeper, which gives users control over which apps can be installed.

A software upgrade is nice, but the big news here is that Apple is clearly intent on leading the market in the competitive ultra-thin notebook space. Not only does the Air continue to impress, but slimming a 15-inch full-powered notebook down to the size of the Air, keeps the pressure on Apple’s competitors to keep up.