i think we're talking about all those indie-dance things, like at the Boat, the White Orchid, Queenshead Pub, 751, the Social, Stones Place, Beaver, ect.
on the larger level, AD/D events would be in this family.
last night at Crosstown was pretty nu-rave come to think of it.
it's not really a specific style of music though, and the term nu-rave is basically a joke, and not meant to be taken seriously.
it's a silly term that the band the Klaxxons came up with as a joke when some journalist asked them what they would describe themselves as. it got taken more seriously than they meant it, and some people have started using it to describe all those electro-indie-bmore-mashup-discopunk-whatever parties.