Stardock announces the Entrenchment "micro-expansion" for Ironclad's Sins of a Solar Empire is now available for online purchase and download on Stardock's Impulse service. Here's a description: "Entrenchment adds a host of new features including starbases, defense upgrades, a new defense technology tree, mine fields, and hundreds of enhancements to both the gameplay and graphics of the game." Of course, the original Sins of a Solar Empire is required to play. Word is Ironclad has plans for further micro-expansions over the next year.