I don't think data science would be a hot job if advances in data engineering (arguably, another ill-defined term) hadn't been achieved. Because of this I like this definition of data scientist, although I can't remember where I read it:
"A data scientist is someone who knows more about statistics than your average software developer, but more about software development than your average statistician".
"A data scientist is someone who knows more about statistics than your average software developer, but more about software development than your average statistician".