Originally Posted by slaWter
You are comparing platforms for two different market segments.
The successor to the workstation platform, with chips from the Nehalem/Gulftown generations, is Sandy Bridge E. Not Sandy Bridge.
SNB-E uses a quad channel interface, so Intel actually moved forward here.
The desktop platform never used Triple Channel.
Even though the i7 920 was a very successful CPU and very popular for enthusiasts, it was part of the previous workstation platform.
On top of that, they qualified higher speed memory. Nehalem was actually officially limited to 1333. SNB is rated for use with DDR3 1600. SNB-E, same, but with 4 channels.
Intel loves their market segmentation. Best way to extract the optimum amount of money from each customer (if the customer does not get too confused).