Daniel recently posted on Hawking's comment that "philosophy is dead". I'm inclined to agree with Mattheus; I think it's always best to posit a pretty broad conception of philosophy. This is why Daniel, in economics, and I, in theology, are both nonetheless working towards doctorates in... philosophy. When you try to define philosophy outside of "critical reflective thought concerning stuff," you run the risk of doing violence to its identity and turning it into another discipline. A good chunk of the fields of inquiry enjoying academic institutional backing these days are or derive from philosophy in some sense. Much of the theorizing Hawking goes on to talk about in his lecture could be helpfully conceived of as "philosophizing". It seems like Hawking doesn't take it to be such because it deals with data of some sort, but I don't see why this makes cosmological theorizing in any way non-philosophical.
In conversation elsewhere about Hawking's talk, I brought up the fact that it can sometimes be healthy to question the relationship between philosophy and the sciences, and even to critique philosophy's ability to "keep up" with scientific progress. You see this a lot in philosophy of mind/cognitive science, and you see philosophers of mind critique their own discipline on these grounds. But I take this to be the normal ebb and flow of critical endeavors, and a bit different than what Hawking so flat-footedly said in his lecture. The failure of philosophy to keep up with scientific advances is a failure to helpfully theorize advances in scientific understanding of the world... if one were to divide the project of inquiry into "theories" on the one hand and "data", "observation", "experimentation" on the other (I take such a division to be dubious in the first place, but for heuristic purposes it's perhaps forgivable), then the problem of philosophy not "keeping up" is simply one of theory not adequately pushing against data so that data can push against theory so that theory can push against data... so that we can keep moving towards a helpful conception of the stuff around us or within us. But that's a lot different than just saying philosophy is "dead" (unless you're a theologian and have the luxury of positing resurrections... something decidedly unavailable for Hawking).
I'll close with a point I thought was interesting towards the end of Hawking's lecture. He talks about the sorts of technology that are necessary for current work in cosmology (earlier he mentioned a collider the size of our galaxy! With these standards one might question whether physics as it is currently practiced is itself dead, or at least pretty useless for answering its own questions!). He talks about how the amount of data crunched by physicists is so massive that you can't just use pencil and paper anymore: you need analogously massive computer programs to do the work. But then he says that just as physicists shouldn't become philosophers, he also doesn't want them to become programmers! And he submits lightheartedly that the IT folk be merciful to physicists and make their computer programs simple enough for scientists to use.
I don't think the irony of these closing comments was apparent to Hawking, but it struck me that if physics killed philosophy, then IT is about to kill physics as well. Hawking seemed to admit as much, at least, and then to plead that computer programmers dumb down their own work for the sake of simpletons like himself!