Supposedly the Sempron is the new budget CPU to go up against the Celeron...it will replace the Duron. The Athlon XP will be produced into 2005. If you read between the lines at the AMD Sempron FAQ website, it appears the market will then be evaluated to determine how much longer the XP will continue to be produced.
Some of the Semprons will be based on the XP core, & some will be stripped down versions of the Athlon 64...but these will only be 32-bit processors. It appears they will only have 256kb of L2 cache. Some will be socket A chips, & others will be socket 754...the newer Athlon64 has gotten a new socket (socket 939).
Here's a few sites for ya to chew on:
http://www.amd.com/us-en/Processors/...E88040,00.html
http://www.amd.com/us-en/Processors/...E88041,00.html
http://arstechnica.com/news/posts/20040728-4045.html
http://www.internetnews.com/ent-news...le.php/3387051