Help compile giant list of Amiga hardware vapor

[Lex]

DKB Talon (Zorro gfx, similar to EGS 28/24)
DKB Inferno (gfx addon for Wildfire)
GVP A4098 (Zorro III SCSI)
Sunrize DD-524 (optical I/O for AD-516)
M.A.S.T Infinity Machine (expansion box for A500 with 030)
BSC MemoryMaster 1230 (amiga.resource.cx/photos/memorymaster1230)
BSC TurboMaster 3050 (similar to Blizzard 4030)
Eureka Afterburner (similar to Blizzard 4030)
Harms TurboJet 4000 (similar to Blizzard 4030)
Harms TurboJet 5000 (040 for A4000)
Supra had announced a 040 board for the A3000 in 1990, no name
Silicon Studio (Zorro III sound, www.woden.com/~studio/)

[Lex]

something that was merely announced and something that was actually prototyped and functional

Agreed. And in most cases we cannot be sure if a "merely announced" hardware had no actual prototype behind it. The "giant list of unreleased Amiga hardware" would be better describing the collection.