AMD's native Quad core is just around corner and once again we heard that Intel believes that native quad core is suicide at 65 nanometre. Intel should be able to do it but the yields of such a product would be horrible.
For the time being Intel will prefer to stitch two dual cores and will continue to call it Quad processor. This is the cheaper way as the yields are much better then doing a real quad core.
Intel produces two dual cores and then interconnect them on a same chip and this is the way to do it but you suffer from narrow FSB. Even Intel's Quad core 45 nanometre processor codenamed Yorkfield remain non native. We are talking about two dual core CPU's stitched at a single socket.
AMD has to produce native core that will end up hot and complicated. It will also have a bunch of transistors. It can be done but it might be doomed to have bad yields.
We have two more quarters to see the real answer to this yield question but AMD is committed to go down that road.