Just to start, please fill in with more:
Cave
recent outputs: Akai katana (X360), DDP DFK BL (X360), Muchi-muchi Pork & Pink Sweets (X360).
to come: Dangun Feveron (?)
speculation: starting to change their course, making other games. But it feels pretty safe they will provide us with a decent catalogue of new shooters and ports within the next few years. Is there a risk they go ALL IN on iphone games?
G.Rev
recent outputs: Strania (XBLA), Mamorokun (X360)
to come Ps3 remake of Mamorukun
speculation likely they will re-release Under Defeat and Border Down on xbox 360, at least if strania goes well. It feels pretty safe G.Rev will provide us with a couple more solid shooters before going broke.
5pb
recent outputs: Bullet Soul (X360)
to come DLC for Bullet soul.
speculation Likely they give shooter developing a couple more shots, or maybe they go back to publishing non-cave shooters?
Moss
recent outputs: Raiden IV
to come
speculation: Raiden V?
Milestone:
recent outputs: Milestone Shooting Collection 2 (Wii) Radirgy Noa Massive (X360)
to come
speculation
Triangle Service
recent outputs: Shooting Love 200x (X360)
to come:
speculation:
Doujins:
touhou
recent outputs: touhou.
to come: touhou.
speculation: no need.
Ruminant's Whimper
recent outputs: Hellsinker
to come:
speculation: Hellsinker sequel PLEASE

Blackbird
recent outputs: ?
to come: he won't say anything more.
speculation: Iphone shooter with LOADS of download extras.

Yotsubane
recent outputs: Crimzon Clover
to come:
speculation: