The Inq's got an article up on the dual-layer re-writable format, & how it's pretty much pointless. Though dual-layer dvd's & burners have been around for a while now, the discs are still too cost-prohibitive, & the entire kit & caboodle's about to be replaced by the hi-def discs here shortly...

"Puberty was shorter than the wait for this. Finally, a couple of days ago, the Alliance released of the version 1.0 spec for 2.4x rewriting on Double Layer DVD+RW media – or DVD+RW DL, as it will be known."