Yes, the L4S8A V1.0 supports Intel's Hyper-Threading technology. If you install a CPU with Hyper-Threading such as P4 3.06G on this MB, there is "Hyper-Threading technology" item in BIOS to let you enable or disable this new feature.
The L4S8A V1.0 is built in CMI 9739A Audio chip with additional Dolby Digital decoder which supports up to 6 channels.
Yes, the L4S8A V1.0 comes with SiS 963L chip which supports USB 2.0.
No, the L4S8A v1.0 only supports to DDR333 maximum.