i would guess that they will gradually start creeping into club racing but as soon as anyone starts getting results with one there will be a lot of heated debates for & against all over the net and i guess a rule change/creation, decreeing that they get their own class/heat to run in!
bit like truggys at Slough, Adrian has always said he'd let them race if they have enough for a heat but it very rarely happens! although i imagine an electric buyggy class would be a lot more popular
obviously brushless & Lipo technology has increased runtimes to a new level but at most clubs you run 20 minute finals & often a 30 minute A final! would you realistically see those kind of runtimes?
quick release battery pitstops maybe?
as for nitro, well for a lot of the people who race it - its all about the little engines
quite a few of the 8th guys are old motocrossers like me who like doing a bit of racing on the weekends that lets them still walk on the monday! after all its still 2 strokes, dirt & jumps