ECC 6.0 clarification

hi friends,

some one suggested me for upgrade fro 4.7 to ECC 6.0 it should have this

1. ECC 6.0 works on WAS 7.0 which is a part of NW2004s and 4.7 works on WAS 6.20.

here wat is WAS 7.0 and NW 2004s

2. can anyone give brief idea wat is the benefits we get in ECC 6.0 for abap .and wat will abap in role while upgrading from 4.6 to ECC 6.0

and also pls give any material if u have but except the service .sap id other then that some good id's

regards

soorya