The visuals and information on the fourth CD are now up on the official site. The character for the final CD is Kenjou Ousuke (CV: Ookawa Tohru), and 42 year old business man who runs a company that specializes in importing furniture. His looks and demeanour may be soft, but he approaches every situation with cold logic. The CD will be released on 2013.03.29.
Story of 365 Days
I believe it has been a while since the last release, but the Story of 365 Days is getting a new release. Story of 365 days～floriography chapter.DIA will be released on 2013.03.21. Judging by the title, other CDs might follow later. This CD will feature the King (CV: Hoshi Souichrou), Jack (CV: Hirakawa Daisuke) and Ace (CV: Ono Daisuke) of Diamonds.
Fortissimo (Honeymoon, I love Pet series) is starting a new series soon. "Gyutto Shite" is a series based on the concept of hugging, and it uses the dummy head mic to make it sound like you are really being hugged. Hirakawa Daisuke will be voicing the first CD in the series again (he did the first Honeymoon soon as well). His character is called Serizawa Tsukasa, and he is a 25 year old salaryman working at a large company. He was your childhood friend who and is two years older than you are. Before you started dating you called him 'onii-san'. He has a kind personality, but is also someone you can rely on. While he is normally sweet and very supporting, he occasionally shows a bit more forceful side. His hobbies are reading and astronomical observation (star gazing?). The CD is planned for a 2013.03.28 release.
Futari Kinenbi ('Anniversary Together') is a new situation CD (or series) that is based on the concept of anniversaries. The CD will feature different situations based on different anniversaries (your first date, your first kiss, first Christmas together, etc). The character for this CD is Takaya Hajime (CV: Okamoto Nobuhiko). Wakkannaiyo did a wonderfully detailed description over here, so I'd like point to that for any more details (because otherwise I would simply be repeating what she said anyway).
Tachibana Shinnosuke is returning to the series for vol.15, which will be released on 2013.03.27. Seems like this is part of the 'third series', so there is probably more coming?