Rumour has it that AMD's 45nm K10.5 "Shanghai" processors will be able to jump over 3GHz:
Shanghai K10.5 is a native quad core 45nm and it will be the first AMD to commercially jump over 3GHz speed.
Shanghai K10.5 supports existing boards and DDR2 memory so the upgrade path is easy with this CPU. It is scheduled for second half of 2008 and AMD is still not ready to fix any more accurate date than that. We just hope that it can launch these chips before we have to reach for our autumn / winter jackets.
With this chip AMD might have a chance to get back.