import helloworld project (http://download.devel.redhat.com/devel/candidates/middleware/eap/JBEAP-8.0.0.Beta-CR1.3/ ) -> Run as -> Run on server I got the error (see screenshot).

So I had to change version to 5.0 for eap8: right click on project -> properties -> Project Facets -> Dynamic Web Module from 2.5 to 5.0
And now helloworld project can be deployed to eap8 server.