Strategy Page reports on the first use of the SDB in combat, and explains what makes it unique.
As aircraft like the F-22 and F-35 enter service, which carry weapons in internal weapon bays of limited volume, weapons like the SDB will become increasingly useful. The price is a little concerning, given the number which are likely to be employed due to the small warhead size. Then again the aircraft that will be carrying them aren’t exactly cheap either. The utility of being able to carry many more bombs and missiles inside the jet will be a compelling reason to produce many of them.
I can’t help but wonder if a rocket-powered version with a reduced warhead will be developed later. It would have a longer stand-off range than the unpowered version—somewhat equivalent to an AGM-65 Maverick but physically much smaller and with a different guidance method (GPS rather than TV/IR).
Finally, here is a rather nice, high-resolution video of an SDB being tested in its ability to penetrate concrete structures.
— posted by Nicholas.