For those of us without the drive or the inspiration to create all of our ships from scratch, please add a feature to make the core designs upgradeable. I'd like to be able to call up the basic "Defender," for example, and add new weapons to it. Or call up the basic Colonizer and add better engines. Make it so that the game forces you to save the design under a different name, so it's impossible to overwrite a core design.
If this isn't planned for the 1.1 upgrade, please consider including it in future upgrades.