For I have slipped the surly bonds of Earth . . .

. . . and left'em WAY behind in the dust, this time.  dafydd found this press release on the first successful powered flight of NASA's X-43A scramjet research platform, also known as Hyper-X.  After being boosted to around 3,500mph (5,600kph) and 100,000 feet by an Orbital Sciences Corporation Pegasus air-launched booster, the X-43A made a 10-second powered flight, during which the 2,800lb craft burned about two pounds of gaseous hydrogen fuel, followed by a six-minute unpowered glide to splashdown in the Pacific.  It isn't known at this time exactly what speed the X-43A achieved, but it is designed for speeds approaching 5,000mph (8,000kph)

This is the first ever controlled free flight of a scramjet-powered vehicle and, just by the way, has without the slightest question shattered all existing maximum-speed records for air-breathing vehicles.

Update:

It is now being reported that the X-43A achieved 4,780mph (7,700kph), or around Mach 7, more than twice the previous air-breathing record of Mach 3.2 held by the Lockheed SR71.  This means the X-43A has also broken the X-15's Mach 6.7 record under rocket power, making it (unless I'm badly mistaken) the highest speed ever attained by any winged atmospheric vehicle of any kind.  (The Shuttle attains higher speeds, but does so on the way to and from space; the Martin-Marietta Sprint ABM was also faster, but Sprint is little more than a conical ablative fairing wrapped around a nuclear warhead and the biggest, most powerful solid rocket motor available.)

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( Footnotes )