I was wondering if the TFTP (Trivial File Transfer Protocol) could be built into the Ethernet Arduino's bootloader so that during the loading if a pin was held high or low it would enter TFTP Programming mode which would in essence allow you to program the Arduino via Ethernet, i.e. via the TFTP protocol, something which many Routers and similar network based devices offer.
I am unsure on if it would A. be possible or B. be something people would be interested in, but primarily, C. I have no idea how it would be implemented.
I was looking forward to this because I could swear that was the idea behind the new Arduino ether they were developing, but it has recently limped into the wild with very little fanfare and it seems like it is actually just an arduino coupled with the arduino shield but combining it to one board, instead of two.
I believe john oxer of freetronics had the jump on them on that in his EtherTen
and it even has POE and an sd card.
I know he does great hardware, Im not sure how he is on the software side but I bet he is the one we should be checking in on for this as he definitely has ether and the arduino down.