Gartner (Gregg Kreizmann, at the Identity and Access Summit in Nov 2013) forecasts that by 2020, 70% of all businesses will use attribute-based access control (ABAC) as the dominant mechanism to protect critical assets, up from less than 5% today ABAC is about saying which good stuff should be allowed (whitelisting). This is contrary to most of what the security industry does today, which is saying which bad stuff should not be allowed (blacklisting). Blacklisting suffers from many issues, esp. around accuracy (false positives and false negatives).
However, while whitelisting a la ABAC does not have those problems, it frequently suffers from the complexity overload related to the authoring and maintenance/update of the many, complex, changing fine-grained access rules. As a result, ABAC hasn't taken off as much as it should have by now. Another issue is related to the complexity of the ABAC infrastructure: potentially many attributes have to be aligned, and attribute sources (PIPs) have to be plugged into the ABAC system, and the enforcement end (PEP) also needs to be plugged into the information flow. All in all, this is not a minor undertaking. But it is worth the effort in the long run (the same way IdM and PKI only materialized ROI after a while).
Model-driven security (MDS) policy automation is a critically important part of the ABAC story: It allows the specification of human-intuitive, generic, undistorted policy models, and automatically turns those into the fine-grained, technical ABAC rules. Part of the "secret sauce" is that MDS feeds in other information sources into this process to figure out what rules to generate. MDS also allows the automated checking for compliance/accreditation. See the wikipedia article and our website for details.
In summary, MDS fixes some of the complexity issues that become evident when ABAC gets deployed. Oh, and by the way, we are not the only ones saying that: industry analyst firm Gartner identifies model-driven security as part of "Top 10 Strategic Technologies for 2012", and selected OpenPMF, a model-driven security product, as "Cool Vendor 2008" product.