A couple of years back, Congress passed the Real ID act, which was intended to assert a level on control over and provide a level of conformity to states' drivers licenses. The states, unsurprisingly, weren't necessarily big fans and 17 of them passed laws saying they wouldn't comply. Homeland Security Secretary Skeletor had an answer to those rebellious states: take a loyalty oath , or we're not letting your citizens on planes or in federal buildings come May.
If the rebellious states request waivers detailing how they plan to comply with the law between now and May, then Skeletor will let their citizens continue to board airplanes. If they don't, however, his retribution will be fast and swift (though, notably, they'll have to accept U.S. passports at the airports). In the meantime, all states have until 2011 to issue those of us born after 1964 new licenses compatible with the federal standards or face a similar fate as the rebels.
The states who are currently screwed are: Arizona, Colorado, Georgia, Hawaii, Idaho, Illinois, Maine, Missouri, Montana, Nebraska, Nevada, New Hampshire, North Dakota, Oklahoma, South Carolina, Tennessee and Washington. Maybe it'll make flying United through O'Hare or Denver marginally easier, but I doubt it.
Air travelers stuck in security showdown [LA Times]