American Airlines publishes a chart, perhaps updated weekly, with a rough guide to award availability between select city pairs.
This isn’t nearly as useful as Continental’s real-time availability calendar, but it’s a start.
The city pairs are all domestic, and availability appears to be listed strictly for coach awards, but some disclosure is better than no disclosure at all — although the color coding (white, yellow, green) eerily resembles something from the Department of Homeland Security.