Porsche says that the Taycan will be capable of more than 500 kilometres (310 miles) on a single charge. If this ends up being true then it will be a new class leading EV. There are an estimate 21 test vehicles currently out on the roads, which have managed to rack up around 40,000km so far.
I think anything over 250 miles should be exempt from any range anxiety issues. This is one of the largest battery packs we've seen placed in an EV, so lets just hope that Porsche has taken the necessary precautions to maximize its lifespan.
Going forward I doubt that any new EV will deliver less than 250 miles. Early gen models like the Leaf, helped to bring the technology to the masses, but the benchmarks have risen significantly over the past year or so.
It can be argued that Nissan started the whole transition to EV's, but they have quickly fallen behind new contenders. Neither Toyota or Honda have shown all that much interest in fully electrics, though I have seen some spy shots of the upcoming Urban EV. Looks kinda cool.