Defining Terms

I follow Ed Stetzer on Twitter (I guess a lot of people do). He posted an excerpt of a chapter he wrote in a book called Finish the Mission. You can find that post here: http://www.edstetzer.com/2012/10/finish-the-mission-to-our-neig.html
I wanted to share it because I think he does a good job distinguishing between the terms Missional and Missionary. He wants to protect the term "Missionary" to reflect those people who intentionally cross cultural boundaries/barriers to bring the gospel of Jesus Christ (at least that's how I read it). He's kind of saying we are all sent to work on God's mission, so we are all missional. But there are people called to a special ministry of being Missionaries. What do you think? Is it important to protect that term Missionary? Or are we all called to be missionaries, even to our own culture?