Wait, if things are true, the next lineup of cards are going to be considerably (~30%) faster than current cards. (Radeon has the 8000 series coming up, which is where I got the 30% from, and Nvidia has the rumored "real" 680/70 chip that was held back because it was too powerful for the market.)
It's all about time. I purchased my GPU recently because I'm not waiting for next year to stock up on games since I would be busy with my Masters next year, and this semester is the only time I can use to waste my time gaming. No new games are going to come out this or next year and be 10 times more demanding that our current GPU's flagship performance. If you can wait, wait. Otherwise if you are only going to use your GPU for a year and you wish to get the most out of your computer for that time, get it now.