UpstakeMike, The TW523 is a miserable piece of hardware to interface from the software perspective. Emulating it would be just as ugly. It would also prohibit functionality that will distinguish the new technologies from X10. The software interface to Insteon and UPB is not very difficult and will not be a stumbling block for the technologies.
Squintz, I sent my SDK back because it simply could not do the most basic operations such as accepting a download. The technical support channels were also not setup a few weeks ago to support the product. A developers forum was setup, but all that was there was fellow-developer grief and nothing from Smarthome. Smarthome technical support indicated that Insteon was outside of their scope of support and the developer board was the only avenue of support.
HST is also a beta tester for Insteon. When both HS2 and Insteon are of legal age there will be a marriage.