Yes. The K8 Semprons do support 64-bit OS; it’s the older K7 ones that don’t.
Edit: Just noticed that it’s an E2 version. Will need to check more to be certain.
Edit 2: Well, that's odd - doesn't seem to be an E2 stepping, just an E3. If the L2 cache and flags info is all correct (specifically the fact that it has 128 kB and supports SSE3), then it should have the 64-bit CPU extensions.