More specs for the upcoming 13" MacBook Pro, expected to be revealed this Thursday, have been leaked. The specs, along with a purported photo of the updated laptop's I/O ports, show that the new MacBook Pros are likely to be a very conservative update. However, it appears that rumors that Apple would adopt an Apple-branded version of Intel's Light Peak technology will end up coming to pass.

According to a photo published by MacRumors, the low-end 13" MacBook Pro will receive a handful of changes from the current version. A 2.3GHz dual-core Sandy Bridge Core i5 processor replaced the aging 2.4GHz Core 2 Duo processor. As we predicted, NVIDIA's 320M controller with its 48-core integrated GPU is getting dumped for an Intel chipset, with Apple relying on Sandy Bridge's integrated Intel HD 3000 GPU to offer comparable graphics performance. (Expect 15" and 17" models to feature discrete mobile GPUs.) SDRAM starts at 4GB and clocked at 1333MHz, slightly faster than the current model's 1066MHz.

The "iSight" camera is now referred to as "FaceTime HD." Apple calls the integrated webcams on its latest MacBook Pros "FaceTime" cameras as well, so this is part of that rebranding. The "HD" moniker is unexpected, however. It may be an indication that FaceTime will support higher, 720p resolutions.

The biggest feature Apple is touting is a new "Thunderbolt" high-speed I/O port. We reported Monday on a recent rumor that Apple would be one of the first to offer an initial copper-based implementation of Intel's Light Peak I/O technology, but would brand it with its own name, and Thunderbolt appears to be that implementation. While little technical detail is given, Apple appears to be using the Mini DisplayPort for connecting both displays or Thunderbolt-compatible I/O devices.

Since no known peripherals use Light Peak, we believe that Apple (and possibly third parties) will offer a series of adapters with other ports, like eSATA, USB3, or FireWire, similar to the Mini DP-to-DVI and other display adapters. With a single Light Peak port capable of connecting to multiple devices and up to 10Gbps throughput, it should also be possible to make multiport breakout boxes as well (think desktop dock, or professional audio ports, etc).

Unfortunately, the low-end 13" MacBook Pro specs don't include any other expected upgrades. The standard storage is a pokey 5400rpm 320GB mechanical hard drive, not a fast and durable SSD. The display is 1280 x 800 pixels, not the 1440 x 900 offered on the new 13" MacBook Air that launched last October. And the weight, including the aluminum unibody enclosure, is still 4.5 pounds. While Apple was rumored to be considering Liquidmetal enclosures for weight savings, that apparently won't be happening this time around. However, we are confident that SSDs will be an built-to-order option, and we hope Apple offers the 1440 x 900 display via BTO as well.

As for the remaining MacBook Pros, we expect similar minor updates for those models, including Sandy Bridge processors and the new Thunderbolt port.