I like to think of my Xbox 360 as an 8-bit console, because it crushes the puny competition even more so.
That's a fun dream, whereas the Turbo REALLY IS an 8-bit console. Last time I heard, the X-box 360 was getting crushed by the lame-assed Wii. No I am not this nintega person. I would never disgrace myself by using a name that has any part of the word nintendo in it.
How do you define bit-ness? The CPU is 8-bit, but the graphics chip is fully 16-bit. Further, the CPU in the Genesis is 16-bit, but I suspect (maybe Tom can clarify) that the data bus is only 8-bit. And really, bit-ness doesn't mean much. The SNES has a 16-bit CPU, but the core design is still very similar to the 8-bit CPU on which it is based. And when you take an objective (well, in a relative sense, anyway) measure of CPU performance, like MIPS or somesuch, you find that the CPUs in the Genesis, SNES, and TG-16 all perform on a similar level. So is an 8-bit CPU that's as "powerful" as a 16-bit CPU a lesser CPU because it is 8-bit? Or is it a peer CPU because it can chug out just as much real-world performance?
See, the whole 8-bit console vs 16-bit console thing is really more about perceptions than technical details. It's about lumping together games of similar style and make rather than technical specifications, ultimately. There's no argument that some of the very early TG-16 games were largely 8-bit in scale and scope and meant clearly to compete with the NES. But the later games on the system were very clearly the peers of any of the titles on the SNES or Genesis. It's hard to argue that games like Art of Fighting, Magical Chase, Aero Blasters, Lords of Thunder, etc... are somehow of the same generation of development, graphics, and audio as the NES. These games are clearly peers to anything released on the "true 16-bit" systems. So in this sense, the PCE is a bridge system. It's the system that connects the 8-bit generation to the 16-bit generation. Just as the Neo Geo bridges the 16-bit generation with the 2D games of the 32-bit generation. The N64, with its 64-bit CPU, is clearly of the 32-bit generation regardless of its technical details, whereas the Dreamcast is considered, at least timing-wise, the bridge system between the 32-bit generation and the following generation (PS2, GC, Xbox).
I know I'm beating a dead horse here, rehashing stuff we all largely agree on. There's no point arguing the bit-ness thing any further. Regardless of particular design decision trade-offs and the lack or presence of a particular capability, the PCE is definitely a peer system to the Genesis and SNES. On this I think there is no meaningful debate. It doesn't matter if any one of us likes one system a little better than the others, they're all clearly in the same ballpark and playing the same game, if you will.