Well emulation is when you add a layer that translates the code and system calls for another system, so Trance or E-UAE is emulation since it enables non-native programs to run on MOS.
Its not emulation, in my opinion, to run something like WIPEOUT on MOS because 90% of whats going on isn't emulation, its natively running via clever coding of API, which is what makes MOS so unique. Even today there are programs for win9x that don't run 100% on NT windows, because the architectures ARE different. They do work sometimes due to wrappers and such, and that is emulation.
