Autoscaling isn't really intended for bursting, it works better when you have predictable traffic patterns. But if I understand it correctly you can use EB with custom Cloudwatch metrics and that lets you do some pretty cool, predictive things that autoscale based on external factors such as: volume of Twitter mentions, Google Analytics data, number of active user sessions, etc. In theory you could write some app code that uses custom cloudwatch metrics to initiate scale-up during certain timeframes. right ?