Some of the information is seen on the Duel Jewel.net official website. I merely report it here for English speaking purposes. Remember that some updates may become out-dated and unavailible.
September 30, 2008 NEW RELEASE: Duel Jewel will release an album (which there is two ver.) and there is a pre-sale of the song "against" digitally.
The pre-sale "against" is already availible for overseas download via the site Hear Japan.com. (Thanks to the DJ LJ for the link!!)
The album will be called "Glassfia" and go on sale on 11/26 this year. There are two ver. of the album. The [Limited Edition] is a CD+DVD which includes the "against" PV. The CD plans to contain 10 tracks. The [Normal Edition] won't come with a DVD, but the CD plans to contain 11 tracks instead.
April 14, 2008 NEW RELEASE: Duel Jewel will release a new single (which there is two ver.) and also a DVD!!
The single track is called "Iolite" which I can only assume is related to their tour name which is "IOLITE NIGHT". ("Iolite" is a a blue gemstone out of cordierite >> here). The b-side is a track called "yuu -Yu-". The first ver. of the single comes with a DVD of "Iolite" PV. The second ver. has an additional song called "yakusoku no shi".
The DVD is fittingly called "Jewelry Box". It has 11 tracks, 6 which are previous single PVs and the rest are live tracks from early 2007. I'm most excited about them including a live track of "akatsuki"!!
All three are to release on June, 11.