Not quite what you are after, but maybe one of these may help:
InDesign is (as far as I know) the industry standard for card design, and while it is not specifically made for this purpose, it can most certainly do it, and is the only solution I know of that can directly import a PSD file.
The actual card data can be kept in a separate file (spreadsheet, or possibly other formats) and combined with the card template via the data merge feature, including the image source.
The only real downside for InDesign is price.
For a bit more information on what InDesign can and can't do, see this answer to my own question on the Software Recommendations SE.
Magic Set Editor
Magic Set Editor was originally built for one specific game (Magic the Gathering), but now has support for a large number of games through plugins. I've never actually created an original card type with it, but I have used a few mods and looked into their source as well as used it extensively for creating power cards for 4th ed D&D.
The library of cards is handled internally within each file (each file is a "set" of cards, however you choose to separate sets for your own work) and content can't be merged from an external file, but it does still provide the separation of template and content you would need to allow updating the template without updating every single card.
It hasn't had a release since 2011, but I have never found any bugs with it in the 4-5 years I've used it, and best of all it is free (actually open source).
Initially built for creating custom cards for Arkham Horror, Strange Eons has excellent support for plugins to handle other games and card styles, and while I've never created a plugin for a different game, I did do a bit of development on Arkham Horror-specific plugins a few years ago, and since then its plugin support has only grown better.
Once you have a plugin created for your card type each card you make is saved to a separate file, but cards can then be arranged into decks within the program for printing/organisation.
The documentation also seems to be fairly thorough and helpful, and it is free as well, but is listed here last since it is probably the furthest from what you are actually asking.