With fabrication processes shrinking rapidly, it was only a matter of time before microprocessor companies ran into physical limitations. Uptil the 32nm process, which the current Sandy Bridge CPUs are based on, the existing planar (Flat) transistors could not be manufactured any smaller, and so a completely new design was needed. Their upcoming Ivy Bridge CPUs will be based on the new Tri-Gate 3D transistor design that uses a three dimensional structure rather than the two dimensional one.
Intel has been developing this new transistor technology since 2002 and it's only now that they are ready to use it for mass production. The new Ivy Bridge processors will be the first high volume chips to be produced on this technology and will be coming out by the year end.
So what does this mean to you, the consumer? Well for starters, cheaper CPUs. The new Tri-Gate tech adds a third dimension to the otherwise flat structure, which rises up vertically from the silicon substrate. This allows Intel to pack in the transistors closer to each other thereby allowing them to shrink the fabrication process to 22nm. Going ahead, Intel has the flexibility of raising the fins higher for more performance and lower power draw, so it is scalable as well.
Th flow of current is better controlled here as there are three gates instead of one, so when it's 'On' there is maximum current flowing and when 'Off' there's little to no current leakage. Tri-Gate technology is a necessary evolution as it complies with Moor's Law which states that the transistor densities on microprocessors will double every two years.
While all this is fine and dandy, we are looking at a more immediate problem for end users and that is a new chipset again. Intel's new socket 1155 has only just started picking up as the new B3 stepping begins to flood the market. This chipset will undoubtedly be obsolete next year once the new 22nm chips arrive, which means it makes little sense in upgrading to the 1155 socket if you already have a 1156 socket CPU.
We hope Intel will keep some sort of backward compatibility going ahead, as it's a nightmare for enthusiasts who have the habit of upgrading every year. If your head is still spinning with all this, here's a video explaining Tri-Gate presented by Mark Bohr, Intel's Senior Fellow.