The plan is to have the SDC expandable.
due to the apparent size constraints on the SDC board, there's barely room for an 18-pin PIC, so the number of onboard I/O is limited. Thus far, onboard, in addition to the typical connections for power control, I have placed a temp sensor, some status LEDs, serial lines, and analog voltage measurement to monitor the input voltage. This board will have any settings (like all the delays, thresholds for voltage/temp warnings, etc) configurable by serial.
So there's not really any more room on the SDC board for more stuff. HOWEVER...
the plan is to have an external addon board (this is where the expandable part comes in) that connects to the SDC via a 4-pin connector. since this board doesn't need to be inside the PSU, it can have as much on it as needed. This is where all the "fun stuff" will go... things like various temp and voltage monitors, relay controls, extra status LEDs and control buttons, serial communication with the computer, etc. etc.
The reasoning being that this allows a SDC with moderate features (all the important stuff for an SDC to do, and comparable to the built-in SDC's of other PSU's) to be in the PSU, and anyone who wants more control or features can get the expansion board.