The only true benefit to SATA burners is the fact that SATA is a single-port controller channel. This should not be minimized, it's a considerable advantage. But, it has nothing to do with speed. Same is true for HD's. Most of today's HD's do not deliver data any faster than the ATA-66 drives of some years ago, SATA or IDE, the speeds are the same.
The SATA burners that are available today have cause many issues, due to very poor ATAPI support on the SATA controllers. Until these issues are addresed, there's no real future for SATA burners. For example, ever tried installing Windows from a SATA optical drive? Good luck if you do.
Yes, LiteOn has a SATA drive in their plans, but not until there is a suitable OEM demand for such drives. Looks like the new Sony-chipset based "5" series drives will include a SATA version at some point. Also note that at the present time, none of the beloved LiteOn drive utilities and modding programs will work on a SATA controller.
I think we will see SATA burners put on hold till the next generation of BlueRay and HD-DVD drives are fully implemented. But the bottom line is that it's the hardware makers that are going to decide when they get implemented. Got to have decent ATAPI-friendly SATA controllers first.