I suspect that Popcorn Time is going to be a very popular desktop movie application. Like it or not, there are a lot of people out there who get movies from torrents, and they are bound to find Popcorn Time at some point or another.
You should know a few things about it before downloading it, however. The Popcorn Time FAQ points out that there might be legal issues with watching movies via streaming torrents. That is something to be aware of before using Popcorn Time since the movie industry takes a dim view of anyone who views its content without paying for it.