One issue that's come to pass in the 21st century is the idea of seeing a movie in theatres versus waiting for it to come out on DVD. Both options have their pros and cons, but will one dominate the other anytime soon? I doubt it.
Let's start with DVD's. With DVD's you can pause at any time if say you wanted to take a bathroom break (GMWoolvett, 2008). You can also start watching a movie on DVD whenever you wish, whereas with cinema there is a fixed schedule. With DVD's you can also shout at the characters on screen whereas in a theater you would most likely get weird looks from the people around you (GMWoolvett, 2008).
I think the main reason cinema is still going is because there is a certain experience that goes with going to the movie theatre. You're watching the movie on a huge screen with a more sophisticated sound system. Having such a setup at home is very costly. A Zettel Film reviewer brings up a good point that the big screen can make the viewer feel like an off-screen bystander (Zettel Film Reviewer, 2008). Plus, there are many other people in the theatre with you at the same time so there is an element of a group experience. I witnessed a great example of this when I watched Twilight with some of my friends. When Edward Cullen appeared on screen for the first time there was a bunch of wolf whistling and laughing. It definitely made the moviegoing experience more entertaining than just watching a DVD of it at home.
In conclusion I don't think the cinema experience is dying. I think it will be around for decades to come. Anything could happen so it would be a bit presumptuous to say cinema will be around forever, but I think it definitely has a lot of life left.