It's perfect for gaming: silent, reliable network and Bluetooth, and supports basically any TV or projector. Works great with Xbox Elite controllers.

Only downside is that keyboard/mouse can't connect to Apple TV, so it's controller-only.

I haven't had luck with mouse, but you can actually connect a bluetooth keyboard to the Apple TV. I use a little handheld unit from Rii and it works great.

For mouse, if you have an iOS device you can use the "Remote" widget on your phone as a mouse, and it works in the Moonlight client well enough to click through prompts etc.