What should we accept in the hardware library? Only schematics that clearly include an 8052 somewhere in the design? Schematics of circuits that don't include an 8052 but are often used in 8052 projects? Or include things like FGPA/CPLD which are completely apart from 8052 but, again, may be useful to those working on 8052 projects?

My opinion:

I would say "often used in 8052 projects". For instance a schematic that has often been shown in the threads is multiplexed LEDs and if such a schematic refer to "port pin a, port pin b etc. there is really no need to include the '51 in the "show the principle" schematic. As for FGPA/CPLD I would not include a counter unless it was part of a MMIO, but a MMIO that showed a lot of neat features and were commented to be a "take the parts you need" would be most appropriate.

My opinion for what it is worth

Erik