tyvm, Darkstrumn. that worked great! Can't believe i didn't think to try this as a workaround.
all i did (on OSX Leopard):
adb shell telnetd &
adb forward tcp:9999 tcp:23
telnet localhost 9999
now, to get working on compiling dropbear 0.52 and / or patching adb *eek*
i guess a related question becomes, is there any way to change ash to the default login shell?