In current REST API, we can get only brief pull request information (without title, message, and revision) through the events API as the below:
http://confluence.atlassian.com/display/BITBUCKET/Events

However, it is very useful to users if an API to list recent pull request events with more description is supported. Then, the bitbucket would be widely used with various applications. It will enable the pull request to be one status of jira workflow.