Do you believe Intel rumors that Conroe will intro at 3.0GHz?
That's a tough one. I definitely think Conroe will run at over 3 GHz during its lifetime. However it will be introduced six to nine months or so into 65 nm ramp up. Intel will want headroom to toss out speed bumps over the 15 to 18 months between its intro and 45 nm MPU production. OTOH Intel will want make a very public statement that it is the x86 top dog.
I think if Intel does have a 3+ GHz Conroe at release it will be a EE chip with a sizable price premium. The top end mainstream part will IMO more likely be 2.8 to 2.9 GHz. But don't let the frequency fool you, it will be a top notch performer matched to a great chipset.