DailyTech came across more information about AMD's upgrade to the 65nm process:
Athlon 64 X2 and Sempron processors will be getting 65nm Fab process treatments. Single-core AMD Athlon products will remain on a 90nm Fab process with no foreseeable 65nm future. With the new 65nm Fab process AMD will be able to increase frequency increases of 100MHz increments unlike the 200MHz increments of current products.
This will be interesting as AMD can theoretically abandon all 2x1MB parts in favor of 2x512KB parts with 100MHz frequency differences. DDR2-800 support will be brought to all 65nm processors including the Sempron. This should bring welcomed performance improvements to the AMD Sempron product lineup..
Current motherboards will be compatible with the 65nm processors after a BIOS update. You can check it out over here.