As it stands, if Sonic 2 HD is ported to OS X, it will probably be Intel only, simply because of ease of porting. Cider translates Windows code to code readable by OS X. The way that Cider translates code, however, calls on Intel only addresses and functions, so it cannot be ported to PowerPC using this method. Yes, many do still code Universal Binaries that work both Intel and PowerPC, but to do that you would basically have to recode the engine, which LOst probably doesn't want to do just to have it run on PowerPC processors, and many game developers are starting to make Intel Only games because it is easier to port their Windows code to Intel Macs than PowerPC. Quite simply, it would be far easier to run it all on Intel processors, since it could easily be ported using Cider or Source Code tweaks, both easier than rewriting parts of the engine.