Intel says it's struggling to get enough 45nm cores in both dual and quad variations, and that the two 300mm fabs are up and running and making them as we speak.
At the same time, an Intel spokesman said that they plan to bring online two more fabs, and from that point on the supply of 45nm parts will get better. Two new 45nm fabs should be online in the next few months, but Intel didn’t want to be more specific than that.
This should improve the availability of 45nm dual and quad-core parts, and in Q2 the situation should get much better. In Q3 and onward it should be even better. You can do a lot with four fabs and AMD has only one for the rest of the world.