Intel plans to launch both desktop and notebook version of Ivy Bridge 22nm processor and their platforms in March / April 2012 but in mobile space it only plans to launch quad-cores.
The Ivy Bridge launch list includes extreme mobile Core i7 Ivy Bridge and two Core i7 based quad-cores that fit Intel's performance market P2 and performance market P1. To paint a better picture high end quad core extreme Ivy Bridge replaces Core i7 2920XM, faster quad core non-extreme Ivy Bridge replaces Core i7 2820QM, while the slower version of quad core from P1 market replaces the Core i7 2720QM CPU.
Dual cores, including Core i7 and Core i5 parts based on Ivy Bridge 22nm are scheduled to launch in Q2 2012 while the current guideline indicate that Intel plans to introduce its quad core mobile Ivy Bridge parts and Chief River platform before the end of Q1 2012. One can expect to see Chief River launch before the end of March, but if things get pushed, it might slip to April or early Q2 2012.