AMD has today announced that Sempron processors will be available with 64-bit extensions, bringing 64-bit technology to lower end budget desktop machines. This matches Intel's move which saw the release of five new Celeron D models with 64-bit extensions, and there will be five new processors from AMD to match Intel's Celeron D product line.

The new 64-bit Semprons are available in 2600+, 2800+, 3000+, 3100+, and 3300+ versions and will be offered parallel to the 32-bit versions of the processor. While Intel decided to distinguish its 64-bit Celeron chips from the 32-bit parts with a slightly different sequence number (3x6), AMD's 64-bit Semprons can only be identified by a different ordering part number (OPN).
There is no word yet on availability in the US, however the chips are available right now if you happen to live in China.