AMD's K10 processors are rumoured to offer some sweet performance. It took AMD some time to prepare, but it's said that the 2.5GHz Barcelona/Agena FX processors will be able to beat 3GHz Intel Core 2 Quad processors.
Intel knows it and it is scared. Intel also knows that it cannot go over 3.0 GHz with 65 nanometre, at least not at 120 W TDP. Some reports already claim that QX6850 with FSB 1333 and 3 GHZ clock is already pushing the envelope as intel's 120W TDP is actually 150W+ at least on AMD's TDP scale. TDP stands for Thermal Design Power.
Intel needs to go over 3.0 GHZ to 3.2 or more to match Barcelona / Agena parts at 2.5 GHz. Intel knows that it needs to go to 3.2+ GHz and it needs the 45 nm Yorkfield core to match Agena 2.5 GHz.
The bad news is that the AMD K10 desktop processors won't be widely available this year. In the second half of 2008 Intel is expected to unveil its Nehalem core.