SAP announced it with Business Suite 7. Oracle announced it yesterday with version 12.1 - "rapid value solutions without having to upgrade to this latest release. "
They are being responsive to customer feedback - and pushback that broader release upgrades are invasive, low ROI. An idea which should have been implemented a decade ago.
Two unproven areas, though:
a) Oracle, in particular, has not rationalized support for all its acquisitions. I hear complaints of each product going through its own support lifecycle and related impact on service t&c's. Now they may end up with thousands of customer specific configurations. How easy will that be to support? Technically there are plenty of change/configuration management tools - I am talking about the customer service paths. Similar, though less acquisition-ridden, issue with SAP.
b) What happens to upgrade paths to Oracle EBS 13 or Fusion when they are ready? Or SAP 8 or BusinessByDesign? I am sure someone in each organization has thought about future migrations, but I have not seen it well articulated.