I'd think anything less than a quad core now will be considered disappointing by most.
Apple is unlikely to care about the marketing benefits of quad core.
I wanted to say that the quad core seems to be a total waste as a personal workstation.
But I do have other processes running because that's one of the reasons you might want a quad core is for the headroom.
The 3 will be a quad core and something even more forward in progress than a spec bump.
That is how you go beyond 5GHz on a quad core.
Everyone seems to think quad core will "ruin battery life" when in reality it doesn't matter.
I think dual quad core may be a little overkill.
If you want quad core, you can get a workstation.
There is no reason a quad core couldn't do all of that at once.