As reported on the Google Latlong blog, Google Earth now has a new “traffic” layer which uses the same real-time traffic data that is used in Google Maps.
It’s not especially fancy, but that’s probably a good thing. Sometimes simple is better. The traffic is shown as a series of dots along the highway. Green=fast, yellow=ok, red=slow. The dots are clickable and provide you with the current speed read from that radar.
If I still had a highway commute, I could see myself checking this as I stepped out the door each morning. Nice work, Google!