AMD has decided to launch its Phenom FX at 2.8 GHz this year, but it wants to focus on socket AM2+ more. The decision is quite logical, as far more people will buy AM2+ versions than the expensive FX systems.
The main difference is the socket, as the Phenom FX uses a server 1207+ socket while the Phenom X4 uses socket AM2+. AMD will launch 2.2GHz Phenom X4, 2.4 and 2.6GHz as the fastest ones with faster iterations following in 2008.
The Phenom FX will hit 2.8GHz this year and will go higher early next year.