First of all Key Sounds Label (KSL) is the audio CD publishing branch of the Key visual novel studio. I say audio CD but don't try to get these through Amazon or CDJapan, as the first marks them as software (since their from a software house) and the second doesn't carry them at all. Hello Himeya....
I ordered the Planetarian Drama CDs and OTSU trance remixes recently and will have more information on those when they arrive.
New Discs (All LB you can stop reading here if you'd like.)
リトルバスターズ！エクスタシートラックス: Little Busters! Ecstasy Tracks
All the music added to Ecstasy that was not in the original. An append disc to the OST. This is a Comiket 74 exclusive release for ¥2,000 but Key never keeps CDs exclusive for long (price may change however).
Rockstar Busters! Little Busters Arrange Album
This was a Comiket 73 exclusive but it will be reissued for general sale on 8/15 for ¥2,000. I believe the Ecstasy version of the OP is from this disc.
リトルバスターズキャラクターソング "鈴の密かな恋の唄 / Mission:Love sniper" : Little Busters Character Song "Rin's Secret Love Song/Mission:Love sniper"
Another previous exclusive this will be released at the same time as Rockstar Busters! on 8/15 for ¥1,200.
ラジオCD 「ラジオ リトルバスターズ! ナツメブラザーズ! 」 vol.1 : Radio CD "Radio Little Busters! Natsume Brothers!" vol.1
No cover art available
While this has not been officially announced by Key yet, from the software designation it is clearly a KSL title. This is a collected volume of the streaming net radio show with the expected price of ¥3,000. There will be limited and regular editions of this CD according to amazon but only the regular edition is listed currently.Expected release date is 9/24