As AMD seriously slipped all its schedules Budapest can be expected at late 2007 if not even later. Budapest is K10 core with native HyperTransport 3.0 that will offer more interconnection and should make the dual socket machines fast. You can read about it here.
As Barcelona will be known as B1-Stepping of the K10 core, Budapest the following core will be branded as B2-Stepping and the new revision should enable some higher speeds. Budapest and Agena – Phenom processors should be able to run up to 2.8 GHz and this should give Intel some competition.