With an update to v4.0, the Mac AirPlay server AirServer has gotten the ability to mirror the display of your iPad on your big-screen Mac. This is pretty big, as you can now not only send video and music to your Mac as you could before, but you can make presentations and even play games, wirelessly.
I have tried a few AirPlay servers, and AirServer is easily the best. Once running, it just works, and when you choose an AirPlay device to receive audio or video from the standard iOS playback controls, your Mac shows up in the list (you can choose to have it show separate entries for audio and video). And that’s it. Choose one and the movie or music streams to the Mac, playing on its screen or through its speakers.

AirPlay Mirroring, though, lets you send a live feed of your iPad’s screen wirelessly to your Mac. In the same pop-up menu on the iPad, choose the Mac video option. An extra switch will then appear, allowing you to toggle mirroring. Tap it and you’re in.
On my home 5GHz 802.11n network, it’s seamless. Video is responsive and sound in sync (tip: disable the dual-mode AirPlay option or you’ll get no sound). AirServer has a $4 upgrade for previous owners, and costs $15 for new users. If you play a lot of games, or use video apps that don’t support AirPlay natively, it’s worth every penny.