What is the level of "backwards compatibility" when we talk about 3.5 to 3.0? I would think that this would be the main benchmark when we talk about what is or is not within the range of "backwards compatible." I haven't really given a hard look at the changes along the 3.0 to 3.5 to PFRPG Beta progression, anyone who also has a copy of the 3.0 SRD is more the welcome to.
Would that help define "backwards compatibility" better? I mean in terms of the degree and number changes that would be considered tolerable?