As you can see from this chart, Ada 2012 is going to bring a lot of new stuff to the table. Sure, it’s not as big a step as going from 83 to 95, but there are still some pretty significant things going on.
The reader might feel that the changes are quite extensive but each has an important role to play in making Ada more useful. Indeed the solution of one problem often leads to auxiliary requirements. The desire to introduce stronger description of contracts led to the search for good syntax which led to aspect specifications. And these strengthened the need for more flexible forms of expressions and so on. Other changes were driven by outside considerations such as the multiprocessors and others stem from what now seem to be obvious but minor flaws in Ada 2005.
As with anything else by written by John Barnes, this brief introduction to Ada 2012 is a joy to read. If you’re interested in the new features of Ada 2012, then this is probably the best place to start.