Hello,
Business Delegate is still relevant while using EJB 3.0
Business Delegate reduces coupling between presentation-tier clients and business services, that does not change with EJB 3.0.
However, Service Locator can be avoided by the Dependency injection provided by java EE5.
But, remember, Dependency injection works only for object managed by the container, so, Service locator can yet be useful in ejb 3.0.
Regards,
Sebastien Degardin