if your only running 1080 then this will see you out 2015 with most games at ultra 60+ fps. i wouldn't see a need for a 8xx series if your still getting those frame rates. but if your going to go for 1440 or upwards 3gb graphics may hit a wall in the next 12 months requiring lowering of aa settings in games. bf4 is already between 2.5-2.8gig at 1440 and there are titles that use more now and will be new titles that will use more again. if you want the full 144 fps to make use of your monitor then that card will not cut it in some games now. you will get over 60 in just about everything but i dont think you will be over 144 on most games.
option for more ram would be a 290x or 6gb 780. option for 144hz would be 2 780's or 2 780ti's or 2 290 x or non x. that would see you through to 9xx series at 144hz otherwise i would just stick with one card a be happy with above 60 hz untill the 9xx series