The large private datacenters/ASIC manufacturers are so far beyond home miners in every conceivable way. The difficulty will continue to rise long after mining at home is completely unprofitable.
And if/when difficulty starts to decline, it will never again be profitable for home miners to join back in the game because the massive datacenters will ride a thin line of profitability that will exclude everyone else but the most efficient operations.
I have a feeling this is coming pretty quickly. IT is almost impossible for any home miners to make an ROI atm and i doubt it will be possible at all by the end of the year unless bitcoin price spikes to at least 800.