We have lived with NP \neq P being the prevailing opinion for nearly three decades. If NP \neq P there will be no dramatic engineering aspects coming from the result, as focus has long ago shifted towards heuristics and approximations. If NP \eq P, we may still not know any underlying algorithm for solving TSP efficiently, but there will be hope of finding one and the search will continue.

But it may be more realistic to consider what happens if NP \neq P. The main change for CS will be the shift in the focus of research.

If the proof is correct, there will be a brief flurry in which people find simplifications, restatements, and shallow applications to other areas of research.

But for three decades this has been the motivating problem in theoretical computer science. I think there will be a lot of soul searching, and perhaps a subdued atmosphere in the research community, but then attention will turn back to the topics in which people are actively exploring. However, there will perhaps never again be such a unifying, fundamental problem in CS.