I have a MBPr, ATV3, and a DIR-655 router. Everything wireless and in the same room... and I was streaming 1080p videos from Vimeo flawlessly. There is a delay on the MacBook, but the audio is synced up with the ATV so it doesn't matter.
Definitely couldn't game with it, but streaming web content is no problem for me what-so-ever.
Definitely couldn't game with it, but streaming web content is no problem for me what-so-ever.