.. just answering my own question regarding output from the IEC conference in Wisconsin last year (as most recent state of the art) - the presentations are linked off the agenda, here http://fti.neep.wisc.edu/iec2009/agenda
(as kindly pointed out by their web admin, and previously posted here on the forum - sorry for missing that).
seemingly no experimental studies of cusp flows, apart from some rehashed 2d simulations (from Bussard's originals i think).
also, no geometry investigations like those proposed by Kiteman (though couple of interesting approaches to ring shaped and cylindrical electrodes by the Japanese).
so, both those areas still look open for new experiment. question remains, how to instrument effectively in Famulus's setup?