Ivy Bridge is die shrink (tock) for Sandy Bridge. The benefits would be lower power consumption, and a slight increase in clock speeds. For example, the Ivy Bridge replacement for the i7 2600K would be the i7 3770K, at 3.5GHz, 77 watts TDP, and initial pricing of $332. It is rumored that the new product line will be announced on April 23rd with availability (ie NewEgg) on April 29. Sandy Bridge processors will probably still be available for a few months. I can't tell you what, if any, discounts will be available for them.