All almost entirely different teams: It's probably the biggest thing that held back the game every time. We could never keep the same group (or the technology) together long enough to really build, which is hopefully where BA will have a huge advantage with DBC.
2010 was perhaps the game that 2009 *should* have been, but in those days (according to public sources here:
Do Sony and Microsoft still charge developers money to release patches? it used to cost money every time you patched, and it just didn't make commercial sense. Again, it's got a lot better since then.
However, that said I still think that the upgrade from 2009 to 2010 was well worth the money. It had a large amount of differentiation that perhaps wasn't fully appreciated by the hardcore (although I concede that the new things didn't have a huge amount of "back of box" impact.)
Anyway: I wouldn't want to derail this thread debating whether the grass is a bit blurrier than it used to be...