The buying frenzy was from the fact you could get a opty 144, 146, 148 for $300 or less (when they first came out) and overclock it to at least 2.6Ghz and with it's 1MB cache you end up with a FX-55. Some have manged to get 144's up to 3ghz on air. I paid $250 for my 148, it's running at 3050Mhz and I saved at least $700 from not buying an FX-57.
To be honest I don't know why they came out with a skt 939 opty to begin with since it would/does compete with there FX series. Amd realized this mistake and now everyone wants a cheap FX before AMD does say they aren't making more.