In the short term (less than two years), the value of these domains is unlikely to be significantly greater than the .mobi registration fees. Both are brandable, but .mobi hasn't really developed to the point where many brandables are valuable. If I owned NGEN, I would hold it for three years, market it for sale along the way, and see what happens (but be prepared to lose). It's a solid set of letters, and the perfect end user may come along. I am not as enthusiastic about the potential value of GOFX.