As I recall though, it was very Motorola like at the bus level
IIRC (it's bee a few years) there were a couple of fundamental differences, the 68xx chips had a R/W signal and a CS signal and everything is memory mapped. The Z80 has separate WR and RD signals plus separate select signals for memory and IO.
However it was easy to make them compatible with a couple of AND gates or whatever.
I was thinking about building a programmer for EEPROM that ran off my Raspberry Pi.
Unless you plan to remove the chip for programming you have to dual port the memory chip, easy enough but adds several chips. I had an EPROM emulator on the market that plugged into the EPROM socket and used SRAM with the dual porting added.
I thought since the hex files would already be on it it would make sense to use it for the programmer.
Easy, if you have a valid HEX file you can easily load it into the target memory subject to the above.
How would you propose serving the EPROM data via micro?
Well these old chips weren't very fast eh? Maybe connect the AVR (or whatever) up with pins the same as an EPROM and monitor the CS/RD signals, when you see an active select you use the address to index into an array and provide the data.
This was proposed by somebody here quite some time ago, originally I poo-pooed the idea but it may have legs. Especially if you can control the target CPU's clock.
Adding dual-ported RAM would be easier but uses a few chips, this idea only needs a single chip.
Or build an FLASH emulator for development and drop a chip in when finished, just like we used to do but without the UV light 
Rob