All generation 1 miners will be rendered unless very soon. Gen 2 will get ROI depending on WHEN YOU GET YOUR MINER compared to the rest of the queue and others competing for lower difficulty slots. It is all about when you get your ASIC miner.
The window for ROI on any new hardware will be a short one as soon as they ship because there already exist a huge farm of miners. You will have a small window to mine before difficulty scale with more miners lighting up. I think buying any mining hardware is a very risky proposition because the difficulty scales so high and fast it can render your assets worthless in days not months.