8.9 Beta2 has been posted to the downloads: http://teiid.jboss.org/downloads/
Nexus is having issues so this is not yet available through Maven.
This pre-release builds upon Beta1 to provide performance improvements for dup removal and any usage of our internal table structure and many new fixes. Special thanks to Joseph Chidiac for uncovering a variety of issues from Salesforce to windowing and general planning issues. Expect a candidate release to follow in approximately 2 weeks. At which time we can start on the 8.10 and ideally the 9.0 Wildfly efforts.
The Teiid Team