Casey has done a good job with role definitions and that has made all the difference. It means a young guy like Ed can find the means of having a big impact on games. It means guys with some bad tendencies, like JJ and Barbosa, and Bayless, and Kleiza, can become players that stand out for their overall games on both ends often enough to make ou take notice. I suspect that BC tended to bring in players with some sort of promises to expand their games gain bigger roles for themselves on offense. The result was a mish mash of guys trying to do too much. Now we have guys working together more than in the past, and it likely increases their value. Hell, even guys like Jose and Andrea are becoming much more "respectable" by being forced out of their comfort zones for the good of the team. Proper roles and accountability can do wonders, and Casey is really good at managing those sorts of things.
Yes there is a need for an infusion of talent yet, but the right kind of talent that will make such principles even that much more effective. Talent on its own means little when considering aspirations of contending. Talent placed within the culture that is being created can mean that we start seeing some players arriving and becoming stars soon enough.