The Street Fighter series is from Capcom, and Capcom loves sequels and spin-offs. They're in Capcom's blue and yellow blood! But, what gives for the decade long gap between Street Fighter III: The New Generation and Street Fighter IV? Says Yoshi Ono, the game's producer:
If we look at the history of the series, we had the four officially numbered titles: Street Fighter 1, and II, and then we did Zero, which of course is the Alpha series [in the west] , and then III.
In all honesty, and I feel this way, to a degree — we could have stopped at III and been pretty satisfied. We didn't hit a brick wall, so to speak, but we did pretty much all we could do with 2D fighters by the time we got to III. We were very satisfied with the results, and it was hard to imagine doing more than that; certainly, staying within 2D.
But, we've had ten years to think about it, had a lot of ideas being bounced back and forth. For this series, I almost think that we are better off having waited. It gave us a lot of time to settle down and throw ideas back and forth, think about how we would tackle it... Having that time actually helped us to get the game headed in the direction that it's headed now — which I think is a good direction — and to get us where we are today.
Another reason I think that it's actually better that we let it sit on the back burner for ten years, is that technology has advanced so much in the last decade. There is no way that we could have envisioned arcade boards as powerful as this. The 360 and PS3, certainly, are incredibly powerful compared to what we had to work with ten years ago.
...So, we thought, what could we do to reproduce this art, in motion, literally moving in 3D before your eyes, with modern technology? This would not have been possible ten years ago. There is just no way. So we are finally at a point where technology is aiding us, and helping us to do something that would not have been possible ago.
Fair enough. Let's just not put another ten year weight between Street Fighter IV and the inevitable Street Fighter V, m'kay?
Yoshi Ono Interview [GameSetWatch]