As with all rumors, take the following with a grain of salt until we can receive official confirmation or denial from Intel.
Rumor has it that Intel has decided that consumers don't need to make the jump from 4 to 8 cores without anything in the middle. Instead Intel may have decided that they were going to place three dual-core CPUs on a single die and call it a Dunnington. Here's more on the rumored Hex-Core:
"Dunnington, a Bangalore-designed successor to Harpertown, is still supposed to be relatively hush-hush but Intel has reportedly put three dual-core 45nm Penryn chips on a die the size of a postage stamp and sharing a 16MB L3 cache. Like other Penryns, Dunnington still uses a front-side bus."
While we have to say the whole thing sounds a little suspicious to us, we were also skeptical when we heard the rumor of AMD's Tri-Core Phenoms for the first time.
As for where this CPU would fit into Intel's lineup, we're going to guess that it'll initially be plugging into socket 771 motherboards but it could also make its way to the desktop as the next 'Extreme' Core CPU.