Intel To Release Quad Core CPU In 2006

Probably to reassure investors, Intel CEO, Paul Otellini, has announced the introduction of a 4 core CPU ahead of schedule (Q4 2006 instead of Q1 2007).
This CPU will be a double Core 2 Duo (Conroe) CPU. It will feature 2x4MB of L2 cache and should be clocked at 2.67GHz.
What could explain this decision?
Either Intel wants to respond to some customer needs (Apple perhaps), or they want to increase the pressure on AMD.

JCJ