Empty_5oul,

APC magazine - (Oct 2004) includes an article about the new sempron range.

The Sempron is the replacement for the Duron range.

All semprons except 1 are based on the XP core and are socket A.
these were based on the XP to set the product range for market.

The XP based models are 32-bit and will phase out as the Athlon-64 development program moves forward.

All except the Sempron 3100+ which is new baseline model based on the Athlon-64 and is socket 754 and has a FSB speed of 1600 instead of the old 333 Mhz.

Future Semprons will be Athlon-64 core on socket 754, but there are plans to move all AMD cpus to socket 939 further down the track.

The XP will phase out.

The FX is still in.

The Athlon-64s will drop down into the Sempron range as time goes on.

The Sempron is targeted directly against the Celeron but will also streamline both AMD's product range.

The key advantages over Intel are:
They have delivered ahead of schedule.
The chips are cooler (everyone knew that)
and they run at a lower temp ;)
They have a level 1 cache of 128 Kb against the Celeron 16 Kb level 1 cache.
etc...etc...

The product reviews are being released now across the internet & have more info than I'd like to paraphrase here.