I am not that interested in the Extreme version because I do not overclock my computer and no point paying more for a unlocked clock multiplier when I am not going to use it. I am hoping Intel will have 3000 MHz for the normal edition as well or even more as I am targeting at least 3GHz and above.

And yes, Yorkfield will support DDR3.

Intel Core 2 Extreme QX9650

• Extreme edition features unlocked clock multiplier
• Frequency: 3000 MHz
• L2-Cache: 2 × 6144 KiB
• FSB: 1333 MT/s
• Multiplier: 9x
• Socket: LGA 775

Intel Core 2 Quad Q9300

• Frequency: 2500 MHz
• L2-Cache: 2 × 3072 KiB
• FSB: 1333 MT/s
• Multiplier: 7.5x
• Socket: LGA 775

Intel Core 2 Quad Q9450

• Frequency: 2833 MHz
• L2-Cache: 2 × 6144 KiB
• FSB: 1333 MT/s
• Multiplier: 8x
• Socket: LGA 775

Intel Core 2 Quad Q9550

• Frequency: 2667 MHz
• L2-Cache: 2 × 6144 KiB
• FSB: 1333 MT/s
• Multiplier: 8.5x
• Socket: LGA 775

Source: List of future Intel Core 2 microprocessors