Is it just me, or are you responding to a question about a Macbook Pro not being able to access Airplay with a wiki article about anything but a Macbook Pro being able to access airplay?
I am also having this issue with a recently bought apple tv. I have a MacBook Pro (13-inch, Mid 2009) on Yosemite and I do not see the Airplay icon to mirror my display. I can share my audio without issue and I see the AppleTV displayed as an option in Sound and in iTunes. I cannot mirror my display.
I have a friend here with a 2014 Macbook Air with Yosemite and it can share display, but cannot share audio. It is the exact opposite of my issue with the same AppleTV.
I can share my display from my iphone 5s as well.
Any thoughts or articles that address Airplay issue from a macbook pro?