Recent reports suggest that Intel is working on research for 32-core CPUs by 2010. The new processor will contain a total of 24MB of last-level LL cache split among processor nodes. The CPU is anticipated to contain eight processor nodes with four cores per node and 3MB of LL cache to each node. Intel says that BBUL packaging method (which was actually announced back in 2001) will be just as crucial to attaining these specifications as is reducing transistor size.
Unless they make huge strides in production, this is going to be one large CPU. I guess this begs the question though.. which games will support it? :)