I doubt anyone can predict exactly how long hardware will last since we don't know what we'll be playing but I'd say that CF setup should last you a while. The other thing to consider is that you don't know what kind of performance you'll get from an unreleased card. The 7 series could come out and barely improve the 6 series then you would have waited for nothing.
Unless you have reason to believe that a new generation is going to blow everything out of the water within a month I would recommend upgrading when you can no longer play the games you love at the settings you want. Waiting months for a hardware release doesn't make much sense if your current setup isn't working to your expectations
now.
A bus station is where a bus stops. A train station is where a train stops. On my desk, I have a work station…