AMD has something that it calls Continuous Transistor Improvement, or CTI, and this helps the company to slightly improve and fix its existing cores and transistors and to do it in a short time.

Traditionally, it takes more than six months to make core and transistor changes, but with CTI AMD can do it within six months.

This dynamic of processor tweaks was present from the launch of Barcelona and judging from the fact that B3 revision was ready in March, you should expect a new and slightly improved 65nm core by autumn (fall) time.

Intel tries to introduce a new transistor design every two years, while AMD tries to improve and evolve its existing transistors every six months. AMD believes that its approach is less risky, but at the same time it is less radical.  

This will be the final revision of 65nm K10 production process and this last 65nm K10 should co-exist with 45nm K10.5 products for as long as necessary.