Is there a planned date for Impala 2.8 release ?
Looking forward towards lzo support in impala kudu
Current latest release of CDH5.8.2 is with Impala 2.6, so it is too early to tell when 2.8 will be released, as I don't think there is plan for Impala 2.7 yet.
You can try install impala_kudu from here - http://archive.cloudera.com/beta/impala-kudu/parcels/latest/
The impala version is 2.8