...to be cracked.
GameTap (www.gametap.com) appears to have a working DC emu, called "DCX". I've never heard of this before, but my memory is foggy, but I'm thinking it's going to be an internal Sega project.
Only Mr. Driller and Hydro Thunder are available through GameTap right now, but the emulator itself seems to be generic. The emu itself is packed and hidden within the data files, but a process dump shows the following strings of interest:
The fact that exists is interesting, if nothing else. As news spreads of its existence, one wonders when/if it'll be extraced out and "released".