First off do you use a 4K setup? As pascal will be more focused towards 4K, if you do indeed have a 4k setup than I would wait. Now the question is can you wait? Is your current setup enough for you right now or are you in a hurry to buy a new setup? Sorry if I missunderstood it in your topic as you said you're not in a rush but also said you didn't want it to come out late so I got a little confused there
By your budget you seem to want to get a high end card and here's the problem. Pascal might be out early/mid next year but the high end cards will probably only come out end 2016/early 2017 so if you're not willing to wait that long, I'd just get a 980ti. Honestly with a card like that you'll be good to go for quite a number of years. Not to mention spending too much time waiting in this business is not a good decision as GPU's aswell as CPU's are cosntantly evolving. Something comes out this year, next year there'll already be something better. It's true that since pascal will use a new architecture and a new process (14nm), a wider gap between maxwell and pascal is to be awaited unlike with maxwell and kepler but the gaming improvement over the two generations at for example 1080p will be the same. Don't expect an insanely huge improvement in pascal, what we'll see will be pretty much the same type of evolution we've seen with past generations. Of course as I said, if you do have a 4K setup things might improve a bit more and might be well worth waiting.