Intel today introduced the first mobile "Extreme" branded processor, the X7800, clocked at 2.6 GHz. What's more, Intel has removed over-clocking restrictions, allowing OEM manufacturers or enthusiasts to eke additional power out of the chip if so desired.
Apple currently uses Intel's Core 2 Duo chips at speeds up to 2.4 GHz (the previous top speed) in its MacBook Pro, MacBook, and iMac computers. There is no hard evidence yet that Apple will use Intel's latest chip in its computers.
Intel also announced a new desktop processor today (Core 2 Extreme QX6850 quad-core), however the announcement does not look to have much bearing on the Apple community, as Apple has continually eschewed Intel's Desktop products in favor of Intel's less power hungry mobile products or more powerful workstation/server Xeons.
For interest, the newly announced Intel Core 2 Extreme QX6850 quad-core processor clocks in at 3.0GHz with a new, faster 1333 MHz system bus.