"numerous independent reviews have concluded that the program does not fulfill a major intelligence gap or shortfall, and the original justification for developing this technology has eroded in importance due to the changed practices and capabilities of our adversaries. There are a number of other programs in existence and in development whose capabilities can match those envisioned for this program at far less cost and technological risk."

Well, following the recent successes of Hyper-X/X-43, maybe its a hypersonic SR71 follow-on. It certainly would be
1) Hugely expensive
2) A technological risk
3) Meaningless in todays strategic environment
4) filling a niche that Global-Hawk and space-based optics fill well already.
5) Did I mention: Hugely expensive?

Though if the technology could be transferred out to NASA or infuced back into the civilian space program, I'd be tempted to be for it.