I would say purchase a card now, except AMD recently released a new version of their drivers. By now they should be stable, however, I am not sure because I replaced my R9 290 with an MSI GTX 980 Ti Lightning LE that was on sale.
Currently, my video card is faster than AMD's latest offering. There are a couple of caveats I found with moving from AMD to Nivdia that I have never seen in a review. [The old drivers were properly removed, I was a computer consultant for many years and prepping for new drivers is a very easy process.]
1. There is an UGLY line drawn around everything. I eventually got used to it, many people may not notice it, those that only use Nvidia cards and those with a smaller screens than mine; my screen is a 40 inch Samsung 2 feet from my face, so the lines will look thicker on my screen.
2. For some reason after powering on the computer [cold start] it takes longer for the drivers to load compared to AMD. When I first got the GTX card, I started playing games very shortly after the computer booted into Windows. Unfortunately, some games [with poorly written code or a LOT of code to load] I had all kinds of problems, even computer lock up [freeze] that required a hard boot of the computer - that is a serious issue. I solved it by waiting an extra couple of minutes, such as starting up music to listen to or check email, after that I have had no problems.
If you have the patience I suggest you wait, however, I did not wait because of my screen resolution, as I said I purchased the MSI GTX 980 Ti Lightning LE and it runs every game* I have at more than playable fps and demanding games run smoother than with my R9 290. However, my screen resolution is only 1920x1080p [very fine mesh]. 1920x1080 is still the most used resolution.
* I just wish Flight Simulator X did not require 4.4GHz on my i5 3570K to smoothly run with eye candy turned up with add-on environment and aircraft. [The MSX team thought that Intel would have 10GHz CPUs long before now - or CPUs that had a compatible 10GHz throughput equivalent single thread [made in 2012] before now - they did not anticipate Intel shifting emphasis from CPU speed to more cores and more so - IGP, sorry a little off topic.] Every other game is happy with my CPU running at 4GHz and my 980 Ti Lightning LE. I found that I did not have to overclock it [past Lightning speeds, which it can], games are happy at stock speeds.
I have my doubts that the next gen cards will be able to run demanding games at extremely high resolution on a single card.
I put a lot of information here in case you are still sitting on the fence and how games are running on my computer, as reference.
My question, what video card do you currently have? And, what CPU do you have, as some games are CPU demanding, and the proper CPU and motherboard [data throughput] will be needed to feed a very fast video card [game dependent].