The ArcSight Internal case management features are not widely used. So deploying more automation like
Auto appending the Case creation with more of the Alert Information.
Add existing case feature to append the new correlation event information to the existing Case.
Auto Case assignment and improved workflow process from Rules
Bulk Case deletion from Console
Cases getting appended even after being Closed/Moved -> Not a good thing . We don't want to have the case to append a closed case.
Include Correlation event Annotation in the Case fields
Case fields customization feature like the report template customization from Console itself specific to each correlation category.
This is from the More Automated Features on the ArcSight Cases. If you have more suggestions. This blog is open for suggestions specific to the same.