The ideas of goal weighting and goal utility have attracted attention from many quarters in the soccer analytics community.  One example is the excellent 11tegen11 blog which presents an implementation of the weighted goals metric to the Dutch Eredivisie.  A couple differences between his metric and mine are that he uses the idea of "expected points" as a proxy for opposition quality and that he incorporates in-match result probabilities into his goal value calculations.  I have objections to using the raw odds from betting houses as they are a function of both the result probability and the vigorish, but I like the overall concept.  His Eredivisie results include more surprises in the top ten than my La Liga table, which is what I was hoping for in the first place.