I absolutely believe they will. Streaming will be like every other challenge to cinema, and the novelty will wear off (as did television, video, DVD, home cinema set-ups, etc, etc).

In the meantime, adherents to the true faith (ie cinema) have never stopped going to mid-budget films (or any films for that matter), when they are released. I'm pleased to report that, where I live at least, audiences are definitely trickling back. :)