I understand where you are coming from, but don't really agree with ya. I see all the GF8800's as high end and the 8600's, 7900GS, X1950 pro as more midrange. I guess to you the top 10% is high end. To me it's more the top 30% if there are only 3 classes (high end/midrange/value). But then again, as I said, I see there being more than 3 classes really and high end doesn't have to mean cutting edge, extreme, ultimate, dream, exotic, over-priced, etc.
It's an intersting question and understandable answers will vary. But I personally see his system squeaking into the lower part of high end instead of the upper part of midrange. I refuse to think that you can't find good bang for the buck and still be high end. High end should not have to mean money is no object - e6700 or above and 8800GTX or SLI 8800's. When I am asked about a high end gaming PC now, I think of a single 640MB GTS or 8800GTX paired with an e6600 and 2GB as the sweet spot without going extreme/ overpriced. He is not far enough below that to get booted to midrange in my eyes, but I do agree with the guy who said a high end PC should have a sound card like an X-fi in it.