Proof of concept though this is, Airtight (https://market.android.com/details?id=com.brochos.tva) purports to be the first app that will enable Apple's Airplay on the Google TV. Priced at a mere 99 cents, the app allows you to stream non-DRMed movies to your TV via any Airplay-enabled device like an iPad or iPhone. Music and mirroring are not yet supported and you have to have an update Google TV with the Android Market available.
Because of these limitations I wouldn't recommend that you pick up a GTV just to run Airplay and, because it isn't Apple-sanctioned, expect plenty of breakage down the line. However, it's nice to see some cool apps/hacks are percolating up through to the Google TV, thereby improving the platform for all.
Product Page (https://market.android.com/details?id=com.brochos.tva)
TechCrunch