considering that some 60% of Steam users report they are still using a Core 2 Duo, it really depends on what you are using it for.
Gaming tech has REALLY stagnated until maybe the last few months, in an effort to make games that port to consoles more easily, so you've been able to use 3 or 4 year old tech to play games. DX11 is changing that, and its about the time of the cycle
For example, if you rendering 1080 video, and are still rendering 1080 video in 2016, the 3280 will still offer the same performance, but if video tech has increased and by 2016 you want to render 4K video, the 3280 hasn't improved any to offer similar performance with the new media.
Demand pushes the need to upgrade, it depends on what you are demanding your CPU to do. If you are only demanding internet and facebook, you don't need a CPU any better than the horrible NetBurst P4 :/
Dry