There are some changes from the previous 7.1 version also. You can read about it here: http://pic.dhe.ibm.com/infocenter/wmqv7/v7r5/topic/com.ibm.mq.doc/mq50130_.htm
WebSphere MQ V7.5 Explorer can downloaded as SupportPac MS0T: http://ibm.co/SupptPacMSoT . You can connect to queue managers of earlier WebSphere MQ versions on the Server from this.
WebSphere MQ 7.5 has been released
WebSphere MQ 7.5 version got released a few weeks back. Here's the link to the infocenter: http://pic.dhe.ibm.com/infocenter/wmqv7/v7r5/index.jsp
Here's the link to What's new section: http://pic.dhe.ibm.com/infocenter/wmqv7/v7r5/topic/com.ibm.mq.doc/mq50095_.htm
The two main functions that you get with WebSphere MQ V7.5 are the Managed File transfer and the Advanced message security. With File Transfer feature you can exchange files between queue manager and also reach out to the workstations that do not have MQ Server using the Agents. Advanced message security provides message level security without impacting the end applications.