Beyond Augustine by Dennis Wingo
There are many ideas that have been scoffed at or sidelined, like In Situ Resource Utilization (ISRU) that could be brought back into the mix. Ion propulsion space tugs are also much closer to reality than what most people think. Advanced computers and electronics could be introduced into space as well. There is no reason for not flying state of the art computers, software, and advanced analysis capability. This reluctance to use the advances in computers in space that we take for granted on the ground is a major impediment to lowering the operational costs of space exploration.
Dennis makes great points in this article that, if we are slowing down our post Shuttle/Station Program we can use the time to figure out how to go beyond LEO cheaper and better, even if it is slower.