Today a study will come out saying that Spark is eating Hadoop -- really! That's like saying SQL is eating RDBMSes or HEMIs are eating trucks.
Spark is one more execution engine on an overall platform built of various tools and parts. So, dear pedants, if it makes you feel better, when I say "Hadoop," read "Hadoop and Spark" (and Storm and Tez and Flink and Drill and Avaro and Apex and ...).
The major Hadoop vendors say Hadoop is not an enterprise data warehouse (EDW) solution, nor does it replace EDW solutions. That's because Hadoop providers want to co-sell with Teradata and IBM Netezza, despite hawking products that are increasingly eating into the market established by the big incumbents.