Since you need I2C, you need to get parts of the south bridge working.
Even though it's on the DIMM? Ugh. :(
So, its basically the same amount of work as with the USB debug port.
Yeah. Not much point to it then.
Well at least it's an I/O BAR instead of a memory BAR, quite a bit easier to do portably.
Question is: Will we see systems without USB (debug port) but with DDR2 sockets?
See wiki page with list of EHCI chips that lack the debug port. On the other hand maybe all boards using them will have a serial port?
Lots of boards don't have USB... Remember, the desktop market is only a very small percentage of the total (Linux) market!
Segher