Apple at its developers conference Monday unveiled plans to transition its 13-inch unibody MacBooks into a more premium offering by announcing plans to rebrand them as 13-inch MacBook Pros alongside more affordable pricing. MacBook Airs were also updated with cheaper pricing.

Apple said it will retain the "MacBook" moniker for its white $999 MacBook which ships in a polycarbonate enclosure. The new unibody models include a 2.26GHz model for $1199 and a 2.53GHz model for $1499, down from $1299 and $1599.

13-inch MacBook Pros

The new 13-inch MacBook Pro is a significant upgrade at a lower price than the original aluminum MacBook it replaces. With the same unibody design popular with consumers, students and professionals, all 13-inch MacBook Pro models now include a seven hour built-in battery, an SD card slot, a FireWire 800 port, an illuminated keyboard and an improved LED-backlit display with 60 percent greater color gamut.

Also featuring NVIDIA's GeForce 9400M integrated graphics processor, the 13-inch MacBook Pro is available in two models: one with a 2.26 GHz Intel Core 2 Duo, 2GB of RAM and a 160GB hard drive priced at $1,199, and another with a 2.53 GHz Intel Core 2 Duo, 4GB of RAM and a 250GB hard drive priced at $1,499.

"Across the line, all of our new MacBook Pro models now include Apple's innovative built-in battery for up to seven hours of battery life, while staying just as thin and light as before," said Philip Schiller, Apple's senior vice president of Worldwide Product Marketing. "Starting at just $1,199, the aluminum unibody MacBook Pro is more affordable than ever and sets a new standard for environmentally friendly notebook design."

The 2.26 GHz, 13-inch MacBook Pro, for a suggested retail price of $1,199 (US), includes:

Â — Â 13.3-inch widescreen LED-backlit 1280 x 800 glossy display;

Â — Â 2.26 GHz Intel Core 2 Duo with 3MB shared L2 cache;

Â — Â 1066 MHz front-side bus;

Â — Â 2GB 1066 MHz DDR3 SDRAM, expandable to 8GB;

Â — Â NVIDIA GeForce 9400M integrated graphics;

Â — Â 160GB serial ATA hard drive running at 5400 rpm, with Sudden Motion Sensor;

Â — Â a slot-load 8X SuperDrive(R) with double-layer support (DVD+/-R DL/DVD+/-RW/CD-RW) optical drive;

Â — Â Mini DisplayPort for video output (adapters sold separately);

Â — Â built-in AirPort Extreme(R) 802.11n wireless networking and Bluetooth 2.1+EDR;

Â — Â Gigabit Ethernet port;

Â — Â built-in iSight(R) video camera;

Â — Â two USB 2.0 ports;

Â — Â one FireWire 800 port (FireWire 400 compatible);

Â — Â SD card slot;

Â — Â one audio line in/out port, supporting both optical digital and analog;

Â — Â glass Multi-Touch trackpad and illuminated keyboard;

Â — Â built-in, 58WHr lithium polymer battery; and

Â — Â 60 Watt MagSafe(R) Power Adapter.

The 2.53 GHz, 13-inch MacBook Pro, for a suggested retail price of $1,499 (US), includes:

Â — Â 13.3-inch widescreen LED-backlit 1280 x 800 glossy display;

Â — Â 2.53 GHz Intel Core 2 Duo with 3MB shared L2 cache;

Â — Â 1066 MHz front-side bus;

Â — Â 4GB 1066 MHz DDR3 SDRAM, expandable to 8GB;

Â — Â NVIDIA GeForce 9400M integrated graphics;

Â — Â 250GB serial ATA hard drive running at 5400 rpm, with Sudden Motion Sensor;

Â — Â a slot-load 8X SuperDrive with double-layer support (DVD+/-R DL/DVD+/-RW/CD-RW) optical drive;

Â — Â Mini DisplayPort for video output (adapters sold separately);

Â — Â built-in AirPort Extreme 802.11n wireless networking and Bluetooth 2.1+EDR;

Â — Â Gigabit Ethernet port;

Â — Â built-in iSight video camera;

Â — Â two USB 2.0 ports;

Â — Â one FireWire 800 port (FireWire 400 compatible);

Â — Â SD card slot;

Â — Â one audio line in/out port, supporting both optical digital and analog;

Â — Â glass Multi-Touch trackpad and illuminated keyboard;

Â — Â built-in, 58WHr lithium polymer battery; and

Â — Â 60 Watt MagSafe Power Adapter.

Build-to-order options for the 13-inch MacBook Pro include the ability to upgrade to 8GB 1066 MHz DDR3 SDRAM, a 250GB 5400 rpm, 320GB 5400 rpm or 500GB 5400 rpm hard drive, a 128GB or 256GB solid state drive, Mini DisplayPort to DVI Adapter, Mini DisplayPort to Dual-Link DVI Adapter (for 30-inch DVI display), Mini DisplayPort to VGA Adapter, Apple Remote, Apple MagSafe Airline Adapter and the AppleCare Protection Plan.

MacBook Air

Apple today also updated its thin and light MacBook Air, making it more powerful and more affordable. Measuring just 0.16 to 0.76-inches thin and weighing just three pounds, the MacBook Air is available in two models starting with the new entry price of $1,499 for a 1.86 GHz Intel Core 2 Duo system with a 120GB hard drive and NVIDIA GeForce 9400M graphics, and a 2.13 GHz Intel Core 2 Duo system with a 128GB solid state drive and NVIDIA GeForce 9400M graphics for $1,799.

Every Mac notebook achieves EPEAT Gold status and meets Energy Star 5.0 requirements, setting a new standard for environmentally friendly notebook design. Each unibody enclosure is made of highly recyclable aluminum and comes standard with energy efficient LED-backlit displays that are mercury-free and made with arsenic-free glass. All MacBook Pro and MacBook Air models contain no brominated flame retardants and use internal cables and components that are PVC-free. The built-in battery design results in less waste and depleted batteries can be replaced for $129 or $179, which includes installation and disposal of your old battery in an environmentally responsible manner.

Availability and upgrading to Snow Leopard

The new 13-inch MacBook Pro and MacBook Air are available immediately through the Apple Store, Apple's retail stores and Apple Authorized Resellers.