Besides the two earlier mentioned enhancements in my post from Friday, the new feature which caused regressions when it got introduced in Patchset 6 has been fixed. This is why Patchset 6 got password-protected short after it was released.
Object Instantiation Changes Starting from Siebel 220.127.116.11/18.104.22.168 PatchSet 7 and later (Doc ID 1668366.1)\
Essentially this change modifies the behavior of script execution within the [general] section of objects. Behavior can be controlled using the System Preference “Defer Object Initialization”.
Of particular interest: the phase-out approach. While on IP13 no differences unless customers explicitly selected to enable object initialization. With IP14 the new behavior becomes default, but can be disabled. With IP15 customers are required to adopt the fix.