When I was given the charge of writing and designing all of the future Oathbound materials, (starting with Wildwood and moving forward), there were four major obstacles/barriers, whatever you want to call them, that I felt needed to be addressed to take the setting to the next level so to speak.
1) Art- The art from the core rulebook, Domains of the Forge as well as Plains of Penance and Wrack and Ruin elicited only two responses-love and hate. Although I'm not certain of the percentages for each category, I'm pretty certain that the latter was certainly the more vocal of the group. Since then, we've moved away from the sinewy and highly stylistic art to more realistic or traditional fantasy art. The cover for Wildwood is a good example of the "new" look for lack of a better term. So if the art from the early books turned you off, it's pretty much gone in the latter supplements. Also the Wildwood maps were drawn by the guys from Inner Circle Games, (Denizens of Avadnu for those unfamiliar with them), so the maps are simply off the charts in terms of quality.
2) Epic Gaming- I've made a conscious effort to move the later materials, starting with Wildwood, away from emphasizing epic characters and more towards a "level neutral" approach. The disclaimer that Oathbound characters should be 7th level or higher to start off is pretty much history in my mind and in the product.
3) Rules Issues- Prestige races have undergone a major overhaul, and all of the classes and races have been updated to 3.5 (these updates appear in Wildwood and the Oathbound Player's Guide which is to follow). Other mechanical aspects of the campaign setting have also been reworked considerably, (channeling comes to mind immediately, but there are others.)
4) Anthropamorphic races- Again, some people like furries and others hate them. I'll just say this. Future Oathbound supplements after Wildwood-which has two humanoid races, two furries and one that really doesn't fit in either category, will feature far fewer furries than earlier ones.