Why philosophy? Mindful of truly urgent issues like climate change and the gulf oil gusher, if the question is existence or extinction, doesn't merely thinking about either seem a dubious luxury?
It depends on how you think of philosophy. If we think of it as an abstruse set of problems - then yes it does seem a luxury. Like doing crossword puzzles. On the other hand, philosophy is about the love of wisdom, which has much to do with a knowledge of how to live. And there can be no doubt that wisdom would be helpful in solving the world's problems. Of course, degrees and publications in philosophy are no guarantee that a person has wisdom.