Universal is set to roll out the first Blu-ray/DVD "flipper discs"--a single, dual-sided disc that contains Blu-ray on one side and DVD on the other. The "Bourne" trilogy ("Identity," "Supremacy," "Ultimatum") will be the first movies to get the dual-sided treatment, with all three discs coming out on January 19.
The flipper discs are a good idea, as one of the biggest drawbacks to Blu-ray is that new movies you buy can't be played in DVD players. That loss of flexibility can be a real pain in locations other than your home theater (car, plane, bedroom), where you probably haven't upgraded to Blu-ray yet.
On the other hand, the flipper discs aren't quite as attractive an option as the increasingly popular Blu-ray-DVD combo packages that include separate discs for both formats. Overall, Blu-ray-DVD combo packages offer more value--you do get two discs to take anywhere you like. The only advantage flipper discs might have is if they can drive down the price of the movies.
HD DVD fanboys (somehow they still exist) will also be quick to point out that this is hardly new technology. HD DVD/DVD combo discs were around back in 2007; in that sense, it's unbelievable that it took Blu-ray this long to get onboard with a good idea.