With the Dreamcast resurfacing recently in the news, the Escapist's interview with the guys behind Cryptic Allusion — one of the pioneers of the Dreamcast homebrew scene that is waning — is pertinent. Even though Cryptic Allusion has shifted away from Dreamcast homebrew, the interview is taken up with talk about what they did do for the scene, where it's at now, and where it may be in the future. On the question of whether they'd like to see Sega try and re-enter the hardware market:
Sega is no good at marketing hardware anymore. Sorry, guys, it's true. The Saturn was a total flop outside Japan, and, while the Dreamcast did pretty good, it got trounced by Sony's PlayStation 2 marketing.
Old consoles had a lot of very custom hardware in them, and you really had to re-learn how to code in a lot of instances. Look at today's console lineup: basically, all PPC cell processors with various combinations of off-the-shelf video hardware and such. Modern arcade boards are more or less just a consumer console crammed into a JAMMA form factor.
So, in that sense, no, I don't expect nor would I like to see Sega return to the hardware scene. I like them doing what they did during the Dreamcast era: making fun games. Hardware is just not all that interesting anymore.
If you're nostalgic for the days of yore, it's worth a read through. It's certainly an interesting look at the pleasures and pitfalls of trying to keep a dead console alive.
Interview: Cryptic Allusion on Keeping the Dream(cast) Alive [The Escapist]