FLEX-33328 - Merge Adobe.next bug fixes and new features into spark DataGrid. The new features include the new properties lockedRowCount, lockedColumnCount, multiColumnSortingEnabled, and moving and sorting columns via the keyboard. The DataGrid does size a bit differently mostly due to bug fixes. The skin changed because of new parts introduced for the locked rows and columns so custom skins need to be upgraded which is easy to do. The mustella tests for the existing features pass on OSX. No mustella tests have been added yet for the new features.
The new features may need a bit more work but given all the existing tests pass the DataGrid should be pretty stable if you don't use any of the new features.