Is Mr.Porter’s theory of Market Signaling relevant in today's contemporary times?

I think its relevant today but depends upon those strategies which are intended to signal the public.  In this era of technological progress, information are available to anyone. So your market signals could be analyzed from a facebook link to Research & reporting firms. Also people are more focused on their needs and customizations than ever before, so bluffing is out of question. Therefore to receive advantage of a market signal, I think the segmentation and targeted product range must be precise, that could help the firm to hold themselves in a situation of negative market signaling.

Also an long-term pre planned signaling strategies could be effective in this era as against the nature of porter's short term strategies.

well i belive human should use every possible tool before making the decision. as no one know for certain whats going to happen actually. so the best one can do its to make the decision, by the information in hand and hope that it is the right one. and in my view Mr Portor have given the business world the right tools to make the decision. just one need to implement them properly. 

I believe it is more relevant today than ever before.It clarifyies directions. It is like a compass which is much needed during turbulent environments.