In mid of February 2013, Apple updated its Retina Macbook Pro lineup with new CPUs. The new mid-range MBP offers same performance as the high end 2012 Macbook Pro. Same applies for the new low end retina Macbook Pro which has same performance as the mid-end 2012 Macbook Pro. Here is a Macbook pro 2013 vs Macbook Pro 2012 comparison
The 13 inch Macbook Pro with Retina display starts at 1500 dollars with 128GB flash and 1700 dollars for the Core i7 2.6GHz processor with 256GB of flash storage.
The 15 inch Macbook Pro features Core i7 2.4GHz quad core CPU and the top-of-the-line 15 inch Macbook Pro features i7 2.7GHz processor backed by 16GB RAM.