Apple's new Mac Pro line-up, with dual-core Intel Xeon processors, looks attractive and powerful from what we can tell here at the Apple Worldwide Developers Conference. I thought I'd highlight a few things.

More memory: the Mac Pro supports up to 16GB of 667MHz DDR2-SDRAM with a 256bit wide memory architecture. That's twice as wide as the memory bus of the G5 Power Mac.

Second optical drive: Apple says the space savings from the new Xeon processors made room for an optional second optical drive, although that drive currently supports neither Blu-ray Disc nor HD-DVD formats. (Apple is on the board of the Blu-ray Disc Association, so draw your own conclusions.) And if you don’t want a second optical drive, you can't use that bay for anything else.

Four drive bays: the Mac Pro has four, easy-access hard drive bays capable of storing up to 2TB worth of SATA drives. The bays don't require tools for swapping out drives.

SLI denied: Apple's graphic board options - nVidia's 7300 GT, ATI's Radeon X1900 XT, and Nvidia's Quadro FX 4500 - support neither nVidia's SLI nor ATI's CrossFire multi-GPU configurations. All cards support dual-monitor setups, with the X1900 and Quadro FX cards supporting dual 30in display setups.

Three free PCI Express slots: speaking of graphics, the Mac Pro offers three open, double-wide 16-lane PCI Express graphics slots (the fourth slot seats the graphics card). You get 300W maximum for all four slots.