If you wanted to update the the new AppleTV 2.3 firmware and still use Boxee, it's now safe to do so. The Boxee team posted a new version of the USB creator making it easy to get boxee/xbmc onto your AppleTV - even with the AppleTV 2.3 firmware.
Below are the instructions per the Boxee Blog:
- Download the latest version of the USB Creator
- Insert a bootable USB key (1GB) to one of your USB slots and run the USB Creator (disconnect any external USB drives connected to your laptop to avoid crying once you discovered you just formatted a 1TB drive with all your media..). see a video how-to guide.
- Insert the patchstick into your Apple TV and reboot it (i.e. disconnect and reconnect power cord), you’ll see a penguin. this is good. now wait till it finishes the install.
- Remove the patchstick and reboot
- You should now see a new option in the Apple TV menu ‘xbmc/boxee’, go to Update and choose ‘Boxee’. let it do its thing.