Jackson 2.6 went GA in July 2015, almost a year ago by the time of our 4.3 GA release. Let's get rid of the reflective checks and deprecated method calls in MappingJackson2MessageConverter and AbstractJackson2HttpMessageConverter.
FreeMarker 2.3.21 was released in October 2014, as a rather major update. Let's get rid of the deprecated method calls in FreeMarkerConfigurationFactory and FreeMarkerView.
XStream 1.4.5 was released in September 2013. Let's finally require it and get rid of the deprecated constructor call in XStreamMarshaller.