GOOD news, everyone! Have been in contact with Dan Vesel (of VStrom accessory fame... CHERDAN@webtv.net ) and he is in the process of making backrests for the ST. You can see an example on his website. I will be getting mine (for the AltRider luggage rack) this week (apparently easier to do as it's a simple bolt on with no spacers/longer bolts needed) and he is currently working on the standard luggage rack model. I think it's just a minimal modification from the standard VStrom rack.
Dan makes good quality stuff at a reasonable price...just don't ask for chrome.... ::025::
BTW, I am in no way affiliated with Dan or his company but have previously bought his products (for my Strom) and have been very satisfied with them...AND am just happy to FINALLY be getting a backrest for my SO (so she stops smacking my helmet when I accelerate... ::025:
I'll post up some pics as soon as it arrives.