if you check this thread it shows all the models of 10xx cards available
http://www.tomshardware.com/forum/id-3047729/nvidia-geforce-gtx-1000-series-megathread-faq-resources.html
the FTW2 cards have been announced already all the way to the 1060 card, and they are for sale. will be no performance gain but the new cooler is kind of neat and different. for the extra $10 for the 1070 version, it would be worth it just for the neat fan set-up. no price was out for the 1060 FTW2 when i looked last, but it is likely the same minimal extra cost. no reason not to.
as for the amd Vega cards, AMD said last month that we'd see Ryzen in march and Vega following a month after that, which is April. so that's what we're expecting but that's all we got so far. no pricing info, performance info or anything else thus far. but you can bet it will effect pricing in one way or another as any major release does. intel has already been making moves to combat ryzen and we have not even seen it yet. hence the HT Pentiums and unlocked i3 they just released.
is it worth waiting? if you got time to wait, then why not. if you're in need now, then don't bother. get what you can now. but if you can wait, why not, it's not too far off now.